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Products => Test Equipment => Topic started by: sdttn on May 11, 2011, 05:19:47 pm

Title: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on May 11, 2011, 05:19:47 pm
I got the dmm (http://www.uni-trend.com/productsdetail.aspx?ProductsID=605&ProductsCateId=743&CateId=743) from eBay for 65$ I do not know if it worth, what do you think?


(https://sigrok.org/wimg/thumb/c/cc/Old_ver.JPG/400px-Old_ver.JPG)

(https://sigrok.org/wimg/thumb/7/70/Old_ver_front.JPG/400px-Old_ver_front.JPG)

(https://sigrok.org/wimg/thumb/2/28/Old_ver_back.JPG/400px-Old_ver_back.JPG)

(https://sigrok.org/wimg/thumb/8/87/Old_ver_batt.JPG/800px-Old_ver_batt.JPG)

(https://sigrok.org/wimg/thumb/a/a4/Old_ver_pcb.JPG/800px-Old_ver_pcb.JPG)

(https://sigrok.org/wimg/thumb/e/e8/Old_ver_es51922a.JPG/400px-Old_ver_es51922a.JPG)

Newer version

(https://sigrok.org/wimg/thumb/1/18/New_ver.JPG/800px-New_ver.JPG)

(https://sigrok.org/wimg/thumb/7/72/New_ver_front.JPG/800px-New_ver_front.JPG)

(https://sigrok.org/wimg/thumb/9/9b/New_ver_back.JPG/800px-New_ver_back.JPG)

(https://sigrok.org/wimg/thumb/8/88/New_ver_batt.JPG/800px-New_ver_batt.JPG)

(https://sigrok.org/wimg/thumb/a/ae/New_ver_frontCover.JPG/800px-New_ver_frontCover.JPG)

(https://sigrok.org/wimg/thumb/b/b9/New_ver_Knob.JPG/800px-New_ver_Knob.JPG)

(https://sigrok.org/wimg/thumb/8/87/New_ver_lcd.JPG/800px-New_ver_lcd.JPG)

(https://sigrok.org/wimg/thumb/9/91/New_ver_pcb_front.JPG/800px-New_ver_pcb_front.JPG)

(https://sigrok.org/wimg/thumb/6/66/New_ver_pcb_back.JPG/800px-New_ver_pcb_back.JPG)

(https://sigrok.org/wimg/thumb/2/2f/New_ver_es51922a.JPG/800px-New_ver_es51922a.JPG)



You can get full res version of these pics from sigrok wiki page (https://sigrok.org/wiki/UNI-T_UT61E)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Drirr on May 11, 2011, 05:52:33 pm
I think that it is not bad at all. Three years ago i bought UT70B for 120$ :-\. It has no true RMS, worse parameters and no acces to battery.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Kiriakos-GR on May 11, 2011, 06:20:04 pm
I do not know if it worth, what do you think?


Tell us more about your self , and what you do.
So to offer my opinion , about how close you got, at getting the right DMM for your needs.

 

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on May 11, 2011, 07:04:29 pm
I am just a hobbyist.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Kiriakos-GR on May 11, 2011, 07:24:02 pm
I am just a hobbyists.

If so , then you got the most extreme DMM , for hobbyists . :-)

I just hope, that your PC also haves, an true Serial port at the back ( old style one ) .  


 

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on May 11, 2011, 07:55:11 pm
I have USB to RS232 converter cable the software can run with this cable, reading 2 value per second.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on May 11, 2011, 08:11:45 pm
I own several UNI-T multimeters and the UT-81B multimeter/scope. I know a lot is written about cheap meters often having serious issues with build or performance but I can honestly say that the UNI-T meters have yet to dissapoint me in service. For hobbyist use they seem extremely good value for money and IMHO have decent enough build quality for most hobbyist tasks.

After seeing Daves reviews on meters I went out and bought a FLUKE 87 III in 'as new condition'. That meter is my first choice for any measurements that I now make as it is a joy to use and is of superb quality. That does not mean I think any less of my UNI-T products though. Your meter looks very nice indeed and should provide you with good service.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: tekfan on May 11, 2011, 08:30:08 pm
The input protection circuitry looks a bit whimpy but other than that the build quality looks excellent. I like how they didn't use just one of those ICs covered in a blob of plastic. The red board is also a special touch (getting quite tired of all the green ones).

It looks like you've got a really decent meter.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on May 11, 2011, 10:00:26 pm
Thanks for your reply.

By the way the DMM has not backlight function.
But the chip (ES51922 (http://www.cyrustek.com.tw/spec/ES51922.pdf)) supports backlight function. The HOLD button is useless for me so I decided to use this button as backlight ON/OFF button.


(http://img841.imageshack.us/img841/514/mhfuq.jpg)

(http://img839.imageshack.us/img839/3936/5wb1vc.jpg)

Short youtube video. (https://www.youtube.com/watch?v=Ud6ITlbw_QY#)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: DavidDLC on May 11, 2011, 10:20:19 pm
Nice hack !

What you need to do is to adapt a small circuit, so when you press the Hold key for 2 sec. it will turn on the light, if you just press and release the key it will act as regular Hold function key.

Also the circuit should automatically turn off the light after let's say 10~15 sec. to save battery.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: pmrlondon on May 12, 2011, 04:50:50 am
I note that UNI-T tend to use BS1362 fuses - if they are suitable, why not? But then again, it does surprise me. It does bring the problem of someone fitting a higher-rated fuse - 3A and 13A are more common than 1A and 10A.

Nice backlight hack - was the hold function merely "push hold"? That is the main downside with my Amprobe...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ziq8tsi on May 12, 2011, 07:47:41 am
I note that UNI-T tend to use BS1362 fuses - if they are suitable, why not? But then again, it does surprise me.

They are ceramic and sand-filled, with a typical interrupt rating of 8kA.  And very cheap and available compared to DMM-specific fuses.

However, BS1362 fuses are only rated for 250V AC, and consequently the UT61E is labelled "250VMAX" on the current jacks.

So I would say that the choice of fuse is certainly not suitable for an industrial electrician, or anyone working with exotic high voltage supplies.  Even if they never intentionally measure current.

For general electronics use it seems okay.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Kiriakos-GR on May 12, 2011, 11:38:32 am
Well , just the fact that UNI-T uses High Energy Fuses (capable to handle Arc - Flash ) ,
on instruments that are intended to be used at low-energy sources  ( Amperes ) ( CAT I ) like the wall plug of your home,
proves that they care for the safety factor of their products .
And this is good.

But what pleases me more ,  are that all those explanatory information’s that our Dave ,
Shares with us ,  from his videos and teardowns ,
works out as educational material , and creates an new generation of informed DMM  owners and users.
Who are almost able to identify, by an simple inspection of the inner parts, how the product stands up,
With the modern electrical regulations, or the given specifications’ by the manufacturer. 
( The true bad made DMM’s does not have any hope, in such comparisons )

Even so it is wise, to not mix or compare specifications’, of bananas with apples or with pears.
Example :  low-energy sources regulations and hardware demands VS  High-energy sources = Unlimited Amperes  )

We cause confusion by doing that. 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: saturation on May 12, 2011, 01:33:09 pm
Most excellent and simple hack.  This chip is amazing, its a full Fluke type DMM on a chip, all inclusive.  But I can't find it for sale anywhere. : es51922

Any clues?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fox on May 13, 2011, 11:05:38 am
Just type the number it into Google.
The First Hit is the Datasheet of the Cyrustek es51922, a 22000 count Auto Dmm Chip.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: saturation on May 13, 2011, 11:39:01 am
Thanks I know and have done this, but where you can buy it?  Its not for sale anywhere: ocotoparts, findchips, etc., do not list it.

Just type the number it into Google.
The First Hit is the Datasheet of the Cyrustek es51922, a 22000 count Auto Dmm Chip.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on May 13, 2011, 02:26:53 pm
Most excellent and simple hack.  This chip is amazing, its a full Fluke type DMM on a chip, all inclusive.  But I can't find it for sale anywhere. : es51922

Any clues?


You can ask for sample to Cyrustek (http://www.cyrustek.com.tw).

Nice hack !

What you need to do is to adapt a small circuit, so when you press the Hold key for 2 sec. it will turn on the light, if you just press and release the key it will act as regular Hold function key.

Also the circuit should automatically turn off the light after let's say 10~15 sec. to save battery.

I can't desing the circuit.
The backlight has timer (60sec)
Thanks for advice.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fox on May 13, 2011, 05:20:12 pm
Thanks I know and have done this, but where you can buy it?  Its not for sale anywhere: ocotoparts, findchips, etc., do not list it.

Sorry, should have read your question more carefully.
Btw. Nice Hack.
Dave reviewed the UNI-T UT61D in his 100$ Mulimeter Shootout. Episode #99
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: saturation on May 13, 2011, 07:11:29 pm
Just my feeling on reading the spec sheet, this nice chip can potentially can get them into patent disputes with Fluke if the chip got into the USA; its my guess why its not available for direct sale; its likely available to ODM for end product design.


Thanks I know and have done this, but where you can buy it?  Its not for sale anywhere: ocotoparts, findchips, etc., do not list it.

Sorry, should have read your question more carefully.
Btw. Nice Hack.
Dave reviewed the UNI-T UT61D in his 100$ Mulimeter Shootout. Episode #99
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: stl on May 17, 2011, 02:56:40 pm
I also have this multimeter, as far as I can tell It's a lot more responsive than the UT61D Dave reviewed (but not as fast as my Fluke 12). I'm very satisfied with it, it's very good value for money. The one thing that really annoys me is the lack of an auto off function and on/off button.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ronnie on June 21, 2011, 12:07:42 pm
I think the Analog Devices AD737J is the IC responsible for true RMS measurement.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: kderh on June 22, 2011, 06:00:01 pm
I also have this UT61E Multimeter, apparently mine is an earlier revision with a green pcb and some component placement changes.

The only problem I have with this meter is the sh*tty uA / mA measurement because the shunt resistances are very high which drops up to 1V voltage at 220mA (or 0.8V at 2200uA)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Kiriakos-GR on June 22, 2011, 06:41:52 pm
There is a cure for this little problem ..  :)

Send a message to Dave about this ..   https://www.eevblog.com/forum/index.php?topic=1134.0
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: cuban8 on June 22, 2011, 07:12:21 pm
Yeah, the burden voltage of the UT61E is "shocking", as Dave would put it (there's also the possibility that he would call it "atrocious" instead):
I measured 1kOhm in the microAmps range and 10 Ohms in the mA range. Interestingly, the UT61D that Dave tested was pretty good as far as burden voltage is concerned.
I think I have to build myself a microcurrent device...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on July 09, 2011, 05:34:10 pm
I also have this UT61E Multimeter, apparently mine is an earlier revision with a green pcb and some component placement changes.

The only problem I have with this meter is the sh*tty uA / mA measurement because the shunt resistances are very high which drops up to 1V voltage at 220mA (or 0.8V at 2200uA)

My DMM has same problem 1v @200mA.

Edit: Picproje.org forum üyelerine selamlar.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on January 02, 2012, 04:15:24 am
This thread convinced me that this was a great device for me as a hobbyist. I wanted something a bit better in quality than what I had been using (which was mainly cheap crap). Additionally, the price being what it was finished the deal. DinoDirect right now has it for $46.39 shipped, Link (http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html), initially $56.39 but add the coupon code LikeDX10 to get $10 off that price. Which to me is a great deal for the features is does have. I am not an EE by any means (materials science/nanotech/inorganic chemist by training) so it should work great for my hobby uses.

Additionally, I must say I do additionally appreciate the comments from those discussing the safety aspects and the good/bad quality aspects. I have lurked in this forum quite a bit just reading comments on different devices. As a noob I still have to google a lot of details but I'm getting there.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 02, 2012, 04:49:05 am
This thread convinced me that this was a great device for me as a hobbyist. I wanted something a bit better in quality than what I had been using (which was mainly cheap crap). Additionally, the price being what it was finished the deal. DinoDirect right now has it for $46.39 shipped, Link (http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html), initially $56.39 but add the coupon code LikeDX10 to get $10 off that price. Which to me is a great deal for the features is does have. I am not an EE by any means (materials science/nanotech/inorganic chemist by training) so it should work great for my hobby uses.

Additionally, I must say I do additionally appreciate the comments from those discussing the safety aspects and the good/bad quality aspects. I have lurked in this forum quite a bit just reading comments on different devices. As a noob I still have to google a lot of details but I'm getting there.

Have you only just ordered from them or have you received your delivery? Have you used them before? What's the service like?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on January 02, 2012, 05:28:16 am
This thread convinced me that this was a great device for me as a hobbyist. I wanted something a bit better in quality than what I had been using (which was mainly cheap crap). Additionally, the price being what it was finished the deal. DinoDirect right now has it for $46.39 shipped, Link (http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html), initially $56.39 but add the coupon code LikeDX10 to get $10 off that price. Which to me is a great deal for the features is does have. I am not an EE by any means (materials science/nanotech/inorganic chemist by training) so it should work great for my hobby uses.

Additionally, I must say I do additionally appreciate the comments from those discussing the safety aspects and the good/bad quality aspects. I have lurked in this forum quite a bit just reading comments on different devices. As a noob I still have to google a lot of details but I'm getting there.

Have you only just ordered from them or have you received your delivery? Have you used them before? What's the service like?

Just ordered. To be honest I haven't used them before but I do know they are thought of in a similar vein as DealExtreme and FocalPrice. Take that for what its worth.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 02, 2012, 05:43:01 am
This thread convinced me that this was a great device for me as a hobbyist. I wanted something a bit better in quality than what I had been using (which was mainly cheap crap). Additionally, the price being what it was finished the deal. DinoDirect right now has it for $46.39 shipped, Link (http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html), initially $56.39 but add the coupon code LikeDX10 to get $10 off that price. Which to me is a great deal for the features is does have. I am not an EE by any means (materials science/nanotech/inorganic chemist by training) so it should work great for my hobby uses.

Additionally, I must say I do additionally appreciate the comments from those discussing the safety aspects and the good/bad quality aspects. I have lurked in this forum quite a bit just reading comments on different devices. As a noob I still have to google a lot of details but I'm getting there.

Have you only just ordered from them or have you received your delivery? Have you used them before? What's the service like?

Just ordered. To be honest I haven't used them before but I do know they are thought of in a similar vein as DealExtreme and FocalPrice. Take that for what its worth.

Cheers. I might take a risk and get one too. Price is much lower than anyone is offering on eBay.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 02, 2012, 12:47:20 pm
I couldn't resist one either  :)

Great deal, thanks for the link and discount code.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 02, 2012, 02:19:12 pm
I couldn't resist one either  :)

Great deal, thanks for the link and discount code.

Yeah thanks Pedro!

Lets hope they show up!  :P

I had a look at the data sheet for the chip the meter uses but could not determine the current limit for the back light pin. Anyone have an idea?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 03, 2012, 01:42:02 pm
Good deal. I can't find any other lower price. I am going to order it.
Thanks for the code.
I sold the meter which I modified.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 04, 2012, 08:08:10 pm
Dino Direct emailed me today and informed me that the UT61E order has been despatched and that they will supply a tracking number in the next day or two. All very professional  :)

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 04, 2012, 11:27:08 pm
Same here. They also sent me a picture of my item at dispatch. Not sure its actually mine though  :P

Also, I got the standard free shipping to Aus so it will be interesting to see what the shipping times are like with other members here.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 04, 2012, 11:55:53 pm
Yes the picture was an interesting touch  :)

I attach my picture so you can see if it's a genuine feature of their despatch system or just a gimmick.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 04, 2012, 11:58:11 pm
Yes the picture was an interesting touch  ;)

I attach my picture so you can see if it's a genuine feature of their despatch system or just a gimmick.

Your image is slightly different to mine, but just very slight things like the alignment of the banner and meter itself. Maybe it is the actual product. Interesting concept.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 05, 2012, 12:04:21 am
Your box has a bit of paper on it or possibly minor box damage. It looks like their despatch system snaps every item....very novel and I suppose their way of trying to prove they actually have the items rather than a scam.

Looking forward to the arrival of the meter...but to be honest I need another like a hole the the head ! There must be a medical term for people like me who 'collect' more test equipment than they can possibly use on a daily basis  :o ....and no that is not an open invitation to call me names  ;D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 05, 2012, 12:09:04 am
Yep I did notice that rip/paper also. I wish these guys sold a bigger range of gear like Rigol etc cos the prices are great. If this thing actually arrives I think I might get another one so I can replace my crappy Jaycar meter im stuck with at the moment. Still in the process of putting a lab together but finding test gear has been a fun experience, just need a power supply and function gen now.....the search continues.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 05, 2012, 12:44:20 am
My order status is still "Order paid".   >:(
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 05, 2012, 12:48:41 am
My order status is still "Order paid".   >:(

Did they send you an email telling you that it was sent? I had to check with them on live chat to see what was going on because I got sent an email but the portal was showing only "order paid". According to customer service there are a few customers experiencing this.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 05, 2012, 12:57:25 am
My order status is still "Order paid".   >:(

Did they send you an email telling you that it was sent? I had to check with them on live chat to see what was going on because I got sent an email but the portal was showing only "order paid". According to customer service there are a few customers experiencing this.

No, they did not. I also didn't send an e-mail.
Should I send an e-mail?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 05, 2012, 12:58:44 am
My order status is still "Order paid".   >:(

Did they send you an email telling you that it was sent? I had to check with them on live chat to see what was going on because I got sent an email but the portal was showing only "order paid". According to customer service there are a few customers experiencing this.

No, they did not. I also didn't send an e-mail.
Should I send an e-mail?

Jump on the live chat with them. Log into the portal and there is a link for it under customer service.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SteveLuck on January 05, 2012, 08:40:10 am
As per Dave's advice on lab set up I ordered two UN61C a few days ago.  Looked like a pretty close match to the UNT meter that did well in his $100 shootout.

I also bought from the same source - Dino Direct.  I've got a cute picture of one meter siting in a basket (maybe its on top of the second one  :)  ) I've got a  tracking number for EMS tracking that links to a google map that shows the meters still sitting in some sort of handling or sorting centre in China.

Have a good look at Dino Direct many of the prices are very close with different specs.  The UN61C seems to list a lot more functions than the UT61E and have a slightly bigger screen for less money (Not much less) maybe its less accurate. Doesn't require a backlight hack though.

I'd love to see a review of some of the oscilloscope type multimeters available.   Desk top and storage space is at a premium small has a lot of appeal over accuracy at a beginner level.

(Edit - its the Dino site that causes confusion over specs see www.uni-trend.com (http://www.uni-trend.com) to compare model specs and accuracy more easily)  UN61C comes with temp probe but lower accuracy.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 05, 2012, 10:54:32 am
(Edit - its the Dino site that causes confusion over specs see www.uni-trend.com (http://www.uni-trend.com) to compare model specs and accuracy more easily)  UN61C comes with temp probe but lower accuracy.

Another difference is that the UT61E is a true RMS meter where the UT61C is not.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: vk6hdx on January 06, 2012, 04:30:53 am
I ordered one too.  Thanks also for the link and discount code.

Will be nice to have a meter with an extra digit of resolution to add to my collection.

Cheers,
Troy
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: shebu18 on January 06, 2012, 07:13:55 am
is this unit better then the Voltcraft VC-270?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: vk6hdx on January 06, 2012, 07:55:40 am
is this unit better then the Voltcraft VC-270?

The UT-61E is a 22,000 count meter whereas the VC270 is a 4,000 count.  Also the UT-61 is a true RMS meter. 

Also according to the specs it seems to have better accuracy than the VC270 in some modes.

For the price it seems a good buy.  I'll report back when I get mine!

Cheers, Troy
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: vtl on January 06, 2012, 11:51:23 am
How exaggerated are the specs? $70 for a 22,000 count meter at 0.1% DC volts sounds like pretty good value.

Its wierd how variable the quality of UNI-T is though. The $130 UT-71 meter looks like its got incredible specs at 0.025% but teardowns show a pretty average board with glass fuses
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ipman on January 06, 2012, 01:35:00 pm
Who said that is mandatory that 0.025% DMM's should be rated at least CATIII and have HRC fuses?
Maybe there is a market for less protected meters used in let's say, microcontroller bussiness for less than 5V powered boards.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on January 06, 2012, 04:27:38 pm
It's not just that the UT71 series have glass fuses and little input protection, it's that mine came 0.4% out of accuracy.

It IS rated CAT IV 600V and CAT III 1000V by UNI-T...... It will not withstand that for sure so I believe it to be an outright lie on their part that it is actually rated for what they say.

So yes, the quality and design of the UNI-T meters is variable, and that is quite the understatement.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 06, 2012, 07:54:13 pm
Uh-Oh ! Don't get me started  ;D

The Uni-Trend UT804 bench multimeter is a total sheep in wolf's clothing, or to put it in a more crude manner, its a pile of POO !

I am unfortunate enough to own two brand new units.... They are still sat in their boxes under my bench. Both have intermittant faults and contain what can only be described as an average multimeter PCB bolted into the front of a large case. Not one of Uni-Trend's finest moments ! Fortunately the two meters ended up costing me postage only after I complained about the quality to the supplier.... he didn't even want them back....that speaks volumes.

To offset the above comments, I own the following Uni-T kit (and I'm not bragging here...its cheap enough to own lots !)  ;)


UT12A (mains electricity safety safety essential - came free with my UT-81B DSO)
UT33B (5 off bought for GBP3 each !) Good for the car glove compartment.
UT39A (a decent daily workhorse in my home office)
UT58C (everyday workhorse in and around the home)
UT61E (en route to me)
UT70B (Large meter, happy with the performanace and PC interface included)
UT81B (Love it... 40Ms/s DSO, well built & does what it says on the tin. It outperforms my Velleman HPS140i)
UT105 (for automotive work on my Mini Moke - nice big display)
UT201 (well I didn't have an Amper-clamp at the time is was bought....not used it yet !)
UT603 (Decent enough LC meter)
UT804 (The word Crap comes to mind !)
UTD1025C (en route to me - looks nice and was bought cheaply as one channel dead - hopefully repair possible)
UTG9010C (arrived today - looks nice. Initial thoughts are its OK for the price but not as good as my Digimess/Grundig FG100).
UTL17 (the tweezers for SMD LCR checking...work well)

The only one that I have in my possession that fell below my buying expectations (price Vs performance) was the UT804....not a bad ratio really. I own Fluke bench meters and an 87 III and I would not expect the Uni-T products to be equal in view of their price point....BUT there is no excuse for a totally crap or dangerous UNI-T design as they have shown that they can build decent kit.


They look and feel good in the hand, lets hope that the contents of the cases keep up with the looks in terms of performance. If you buy some other Far Eastern built multimeter's, in the lower price bracket, it soon becomes evident how well UNI-T is packaging their product...others often have cheap nasty cases with moulding faults, flash and appalling mode selectors.

UNI-Trend....when they get it right, they are very good value especially for hobbyists.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 07, 2012, 10:53:47 am
I just reviewed Uni-Trend's UTG9010C in this message:

https://www.eevblog.com/forum/index.php?topic=6238.msg81339#msg81339 (https://www.eevblog.com/forum/index.php?topic=6238.msg81339#msg81339)

Not great  :(  1990's technology, poorly implimented.

It appears to me that the 'handheld' and 'bench' equipment lines are different divisions within Uni-Trend. The 'bench' division need to up their game.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on January 08, 2012, 06:07:49 pm
I just reviewed Uni-Trend's UTG9010C in this message:

https://www.eevblog.com/forum/index.php?topic=6238.msg81339#msg81339 (https://www.eevblog.com/forum/index.php?topic=6238.msg81339#msg81339)

Not great  :(  1990's technology, poorly implimented.

It appears to me that the 'handheld' and 'bench' equipment lines are difrefent divisions within Uni-Trend. The 'bench' division need to up their game.

Wow, I am glad that some people were interested. I was kinda worried about coming off like a spammer since my first post was linking to a deal. LOL

Anyways, still waiting on mine, thats the biggest thing that sucks about ordering from chinese dealers.  Having to wait a couple weeks to get your stuff.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 08, 2012, 06:46:04 pm
My order still waiting I tried to contact them via "live chat". I can't get any reasonable answer from dinodirect.

I added two ribbon cables for my old samsung phones to my order. May be, they are reason of delay.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 08, 2012, 06:52:20 pm
Dino Direct have shipped my unit and provided a valid tracking number as promised so you should be OK with them.

Aurora
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SteveLuck on January 09, 2012, 05:03:52 am
One Pair UT61C's received today here in NZ from Dino direct

Manual, Packaging ect all in Chinese  but software in English and Chinese.   English manual available on the Uni-T web site so no bother at all.

The wires going into the plugs on the temp probe are a bit skinny and vulnerable looking, other than that it's built like a brick out house.

Back light is excellent and improves the contrast no end - only stays on long enough for you to take a reading though.

Should do fine for newbie!

Cheers

Steve

(Bugger it! no Serial port to USB adapter included)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: shebu18 on January 09, 2012, 07:50:22 am
Where can i find a comparison of A, B, C, D and E? What has one that the other does not have.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 09, 2012, 07:55:05 am
Where can i find a comparison of A, B, C, D and E? What has one that the other does not have.

Well the E model is true RMS and has best accuracy.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SteveLuck on January 09, 2012, 07:56:34 am
http://www.uni-trend.com/ (http://www.uni-trend.com/)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 09, 2012, 08:40:07 am
Ref the serial port to USB adapter....

I saw the official optional USB lead the other day....it has the optical link on one end and the standard USB 'A' plug at the other so its a pucka job, not just an adapter. The price was a shock though .... GBP28 !

I think one of the half decent Chinese USB to Serial adapters will be more than good enough for the uni-directional data link from the meter  :)

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 09, 2012, 09:16:38 am
http://www.uni-trend.com/HDM_UT61.html (http://www.uni-trend.com/HDM_UT61.html)

The best one is UT61E in the UT61 series.

Pros.
Fast auto ranging, fast respond buzzer, 22 000 count max display, True RMS.

Cons.
No temp measurment, no backlight (no matter you can add it :) )

Edit: True RMS.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: shebu18 on January 09, 2012, 09:31:01 am
It's bad that it does not has backlight, for me personaly true RMS is not usefull. More important is the PC software. I am curious what the minimum sample interval is.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 09, 2012, 03:27:02 pm
It's bad that it does not has backlight, for me personaly true RMS is not usefull. More important is the PC software. I am curious what the minimum sample interval is.
2 reading per second on pc software.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: shebu18 on January 09, 2012, 03:56:19 pm
For some logging it is ok.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dith77 on January 10, 2012, 12:17:42 pm
First of all, a big "thanks" for the amazing knowledge you offer in this forum (as this is my first post!!!)

Has anyone, - ever - received an item from DinoDirect???
I saw this thread and ordered UT61E (thanks PedroDaGr8 for the tip), and later discovered many bad reviews for this site.....
Do you think there is any chance to receive anything from them????  ;D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on January 10, 2012, 03:27:06 pm
First of all, a big "thanks" for the amazing knowledge you offer in this forum (as this is my first post!!!)

Has anyone, - ever - received an item from DinoDirect???
I saw this thread and ordered UT61E (thanks PedroDaGr8 for the tip), and later discovered many bad reviews for this site.....
Do you think there is any chance to receive anything from them????  ;D
SteveLuck in this thread already did and received his (he is in NZ though so it won't take as long). Keep in mind this is a chinese site. YOu will see a lot of bad reviews about not receiving orders because it can take 3+ weeks for a shipment to come in. People get antsy and the chinese haven't quite figured out customer service yet. Combine that and boom, lots of bad ratings.
Title: Re: UNI-T UT61E Multimeter teardown photos/backlight hack.
Post by: grumpydoc on January 10, 2012, 07:42:47 pm
Looking at the backlight hack and reading the ES51922 data sheet the hold button might not be the best to use.

According to the data sheet there is a delayed hold function - press hold for > 2 seconds and the meter will wait 6 seconds before holding the display. Sounds as though it could be useful when you can't look at the display and get the probes on the measurement point. Hold also provides a display test if held for > 2 seconds as the meter is powered on.

Neither of these are mentioned in the UT61E user manual.

Why they didn't just put the extra two buttons for backlight and min/max so that all the functions of the chip could be used - it's not as if that would have lost market differentiation with the UT71 models.

"Range" might be the most useless button out of what's there.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dith77 on January 10, 2012, 08:43:21 pm
SteveLuck in this thread already did and received his (he is in NZ though so it won't take as long). Keep in mind this is a chinese site. YOu will see a lot of bad reviews about not receiving orders because it can take 3+ weeks for a shipment to come in. People get antsy and the chinese haven't quite figured out customer service yet. Combine that and boom, lots of bad ratings.

I hope delay will be the only problem with DinoDirect!!!! I read many bad reviews concerning wrong items, non refunding, not recieving at all etc. Let's hope SteveLuck didn't use his "luck" part to get the item!!!!  ;D

Last time I ordered something from DealExtreme (same thing) took 3 months to receive (Greece)!!!!
But I thing it has nothing to do with chinese people or chinese post. Chinese items from ebay usually arrives within 1 month max....
So maybe these sites have some delay getting the "real thing" from their suppliers, and then send it out for posting.
Title: Re: UNI-T UT61E Multimeter teardown photos/backlight hack.
Post by: dith77 on January 10, 2012, 09:24:39 pm
Why they didn't just put the extra two buttons for backlight and min/max so that all the functions of the chip could be used - it's not as if that would have lost market differentiation with the UT71 models.

"Range" might be the most useless button out of what's there.

I think the hack "sdttn" suggests, can use any key (or not??).

I would try to figure out how an extra button like this can be used instead (at the back of the case preferably)  http://www.ebay.com/itm/6x6x9mm-Tactile-Push-Button-Switch-Momentary-x20-/130579769881?pt=LH_DefaultDomain_0&hash=item1e67292a19#ht_3204wt_972 (http://www.ebay.com/itm/6x6x9mm-Tactile-Push-Button-Switch-Momentary-x20-/130579769881?pt=LH_DefaultDomain_0&hash=item1e67292a19#ht_3204wt_972)

If the chip has the potencial, then the only reason not to use it, is the limitation of the casing (ALL ut61 series use the same case). We can't change the case, but we can drill a nice hole on it!!!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: roguegaston on January 10, 2012, 10:43:51 pm
Does anyone know if the UT61E will work with the QtDMM application?  http://www.mtoussaint.de/qtdmm.html (http://www.mtoussaint.de/qtdmm.html)
Or, does anyone know of any other Linux applications that will work?

I just ordered a UT61E from DinoDirect.  I was going to get the Radio Shack one, but I figure I can always pick one of those up too.

Thanks,

Jason
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sonicj on January 10, 2012, 11:15:18 pm
First of all, a big "thanks" for the amazing knowledge you offer in this forum (as this is my first post!!!)

Has anyone, - ever - received an item from DinoDirect???
I saw this thread and ordered UT61E (thanks PedroDaGr8 for the tip), and later discovered many bad reviews for this site.....
Do you think there is any chance to receive anything from them????  ;D
i took a gamble on a order from dino direct a year or two ago... they had a $50 or so charger incorrectly listed for $7. they honored every order placed before they caught the error. i received the charger a few weeks later in good order.

from what i gather they are hit & miss though...  they do participate on the forum at rcgroups.com so there is a level of accountability over there. i don't shop there out of principle. their site is obnoxious and difficult to browse. the fake user reviews are unacceptable imo. if someone posts another crazy deal like the charger, im not so jaded that i won't place a order, i just don't deliberately look for stuff there.
-sj
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 11, 2012, 11:24:08 am
Does anyone know if the UT61E will work with the QtDMM application?  http://www.mtoussaint.de/qtdmm.html (http://www.mtoussaint.de/qtdmm.html)
Or, does anyone know of any other Linux applications that will work?

I just ordered a UT61E from DinoDirect.  I was going to get the Radio Shack one, but I figure I can always pick one of those up too.

Thanks,

Jason

There is a German guy, he wrote linux app for this meter.
UNI-T UT61E multimeter linux usb logging (https://www.youtube.com/watch?v=6-kJL3KC5OA#)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 11, 2012, 04:53:54 pm
My UT61E, ordered on 2 January 2012, has arrived today in perfect condition  :)

Upon opening the padded envelope I found a brand new unopened official Uni-Trend box intended for the Chinese speaking world. The instructions are in Chinese but that is not a problem as an English manual may be downloaded from Uni-Trend.
All other features of the meter are in English.

I must say the quality of the unit is as nice as my other Uni-T meters and I especially like the neat little R/C/Temp and transistor tester adapter that plugs into the meters 4mm ports  :) This meters design appears well engineered and executed.

Pictures attached.

From this personal experience of Dino Direct, I have absolutely no complaints. The communications were excellent and they delivered the required product in a very reasonable time frame.  Good-on-ya Dino Direct.   


Oh, and they supply a free 'cable tidy' fish for chargers and headphoned etc...in red of course  :)
Aurora
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 11, 2012, 11:21:29 pm
Great to hear it showed up and you are happy with the quality. I placed my order on the same day but have not yet received mine. What shipping option did you use?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 11, 2012, 11:59:41 pm
The cheapest China Post + insurance  :)

I didn't go EMS or courier.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 12, 2012, 12:00:51 am
@Aurora
Can you compare inside structure with my photos in first page?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 12, 2012, 09:23:26 am
Can do

Will take alook this evening

Aurora
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 12, 2012, 09:31:50 pm
Pictures as requested.

There is an ugly modification involving piggybacking of a capacitor but all else seems OK at first glance.

Aurora
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on January 12, 2012, 11:28:23 pm
If the chip has the potencial, then the only reason not to use it, is the limitation of the casing (ALL ut61 series use the same case). We can't change the case, but we can drill a nice hole on it!!!
If the meter is properly designed for over voltages, this will be negated by drilling holes and using buttons not designed for high voltages (only 250VAC for < 1 min). Remember Dave's high voltage DMM destruction videos. Now think what happens if you're holding it in your hand and there's a hole in the bottom without proper sealing.

Pictures as requested.

There is an ugly modification involving piggybacking of a capacitor but all else seems OK at first glance.
Some ugly joints in your last pic. Very little input protection and some old-fashioned trimmers (no closed case calibration). Not impressed by the display connector either. But these (except for the ugly joints) are all design issues, not manufacturing/QA issues. Guess that's why it's cheap.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 12, 2012, 11:41:22 pm
Hi alm,

Totally agree.

I wouldn't have paid more for this and it will never see a high energy circuit  ;)

I just noticed in the last picture a hilarious 'engineering solution'.....to the left of the black 'thing' there are THREE SMD components stacked on top of eachother. Now that is very poor practice for a production unit !

I'm happy for this to me a disposable meter for odd jobs and the price was certainly OK. I'm happier with my UTD1025C purchase though  :)

Aurora
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on January 13, 2012, 12:05:27 am
Where can I find your teardown of that UTD1025C? ;)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dith77 on January 13, 2012, 12:54:39 am
If the meter is properly designed for over voltages, this will be negated by drilling holes and using buttons not designed for high voltages (only 250VAC for < 1 min). Remember Dave's high voltage DMM destruction videos. Now think what happens if you're holding it in your hand and there's a hole in the bottom without proper sealing.

Haven't seen them yet.... (busted) newbie on the forum!!!

Some ugly joints in your last pic.

Really awful details.... I'm still wondering whether I should cancel my order before it is shipped - or not.....
$46 is very expensive if you must pay another $100 to buy a proper one.

I'm just a hobbyist, and didn't want to spend $50 more to buy the chinese Fluke 17b..... but now I'm really worried about the UT61E quality.....
Currently I have a chinese cheap meter (Xiole DT9205A bought from Dealextreme). I was hoping to get a much better one, but UT61E seems more or less equivalent
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 13, 2012, 01:52:35 am
If this meter for $50 is compared to the $50 meters in the shootout, it suddenly becomes better value.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 13, 2012, 01:55:47 am
@Aurora
Thanks for the photos.

There is no big difference.

Will you do back light mod?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: FenderBender on January 13, 2012, 04:06:36 am
That's some of the ugliest SMD soldering I've every seen. Did they grab some random hobo to hand solder them or something? Jeez.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: vtl on January 13, 2012, 04:53:28 am
Looks like the plastic has melted from a soldering iron on that SIP part, is that a resistor network? Leads aren't properly formed too, just bent over which is a bit crappy.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on January 13, 2012, 06:25:20 am
Here's some pictures of the insides on my multimeter.   I got this a few months ago off eBay for... probably 58$ including shipping.

My version has only one SMD piece over the other but the two separate pcb mounted parts are soldered between them.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: vk6hdx on January 13, 2012, 07:45:56 am
There is certainly some sloppy soldering & hacks in these UT61E's.  I'm still waiting for DD to ship the one that I ordered last week.  It looks as though they may have run out of stock.  :-\
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 13, 2012, 01:38:54 pm
dinodirect send me this picture  :-\
(http://a7.sphotos.ak.fbcdn.net/hphotos-ak-ash4/402280_269334316464065_100001624957728_1080504_931673345_n.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: vk6hdx on January 13, 2012, 01:55:08 pm
dinodirect send me this picture  :-\
(http://a7.sphotos.ak.fbcdn.net/hphotos-ak-ash4/402280_269334316464065_100001624957728_1080504_931673345_n.jpg)

 :o WTF is that, it doesn't even match the description.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 13, 2012, 03:27:15 pm
Well its red, just like a Uni-T meter.....don't know what you are worried about..... only joking  ;D

An email to Dino Direct is in order to ensure you get a meter instead of a 'red thingy' !
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 13, 2012, 04:49:25 pm
alm,

To answer your question regarding the UTD1025C....

I have been 'playing' with it since it arrived yesterday to make sure the Channel A issue is the only fault....it is  :)

I now have to build up the courage to start dismantling it.... I am thinking things will be pretty tight inside that case ! I will do a very careful and staged disassembly with plenty of pictures that may be posted on this Blog. Once its apart, the investigation into the cause of its Channel A failure will begin  :)

I'm kind of looking forward to it, yet at the same time dreading what I may find....my eyes aren't what they used to be  :'(  but I do have all manner of optical and electronic vision enhancers available  ;D

I have started another thread on the UTD1025C, progress will appear there.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: vk6hdx on January 16, 2012, 06:29:45 am
Just got my pic from DinoDirect.  At least its looks like the right thing is on its way.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: shebu18 on January 16, 2012, 07:17:21 am
On the display you have a 4000 or 6000 count multi, not a 22000. I will order my from ebay, still china.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: vk6hdx on January 16, 2012, 07:24:04 am
On the display you have a 4000 or 6000 count multi, not a 22000. I will order my from ebay, still china.

I think the same box is used for all the UT-61 series meters most of which are 4000 or 6000 count.  The UT-61E is indeed 22000 count as per the specs @ http://www.uni-trend.com/UT61E.html (http://www.uni-trend.com/UT61E.html), fingers crossed I get sent the right one.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 16, 2012, 08:32:00 am
All UT61 models use the same generic box.

The Dino supplied item is no different to other sources and is a 22000 count UT-61E.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on January 23, 2012, 03:00:31 am
Price shot up on the DinoDirect site. No longer a good deal.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 26, 2012, 11:28:31 pm
My UT61E just showed up after all this time. Only opened it up but im pretty happy with it so far. Only thing it needs is a nicer set of leads. I will tear mine down soon and post pics. Also have the LED's ready to do the mod.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 27, 2012, 01:31:21 am
Here are just a few of the tear down shots, I will post more later. First thing I notice is that this board has a different layout than those in the other images in this thread, particularly in the area where dodgy soldering has been identified. My meters build date is 27 Oct 2011, not sure how that compares with the others.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: plunger on January 27, 2012, 04:44:54 am
(http://img256.imageshack.us/img256/4509/backmeter.jpg)
(http://img441.imageshack.us/img441/7361/meterfront.jpg)

I also got mine in today from a USA source. I took mine all apart and wished that I didn't. The 10A lead pin got bent pretty good while re-assembling. I also put the dial in backwards.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: plunger on January 27, 2012, 08:22:30 am
Are we able to use Fluke leads on this? I'm thinking about buying a set or one from Extech if it it would be ok.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on January 27, 2012, 01:27:07 pm
Fluke leads with 4mm shrouded plugs will work fine....thankfully meter leads tend to follow an industry standard these days.

Aurora
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on January 28, 2012, 09:58:29 pm
Mine finally came in (no clue what the delay was as it looked like it shipped when they said it did). Maybe my package didn't make the boat for chinese new year. :P

Now my general non-pro hobbyist opinions, comments and statements on the meter:
First off, this meter is SOLID. The body has NO give in it at all. Even with the screws removed. The external quality alone is VERY VERY nice in your hands. The rotary knob has a nice feel to it. It feels great when it snaps into the off position. Unlike Aurora my meter came with both an English and a chinese manual (two seperate manuals). My meter has the same modified board that Teknotronix shows. C41 and C42 are moved down closer to the slot (and out from under the resistor array). The resistor array is now vertial and soldered in properly. The changed layout of the capacitorson the side. Now only one piggy back capacitor at C9a. The rest are all normal. Silkscreen has been modified to better match the current part selection (no huge circles around CW1 and CW2). I have no clue how to find the build date.  Honestly, I am supper happy with this. This meter will serve my needs PERFECTLY! It really is kinda overkill for any hobbyist. 8)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 28, 2012, 11:48:41 pm
Mine finally came in (no clue what the delay was as it looked like it shipped when they said it did). Maybe my package didn't make the boat for chinese new year. :P

Now my general non-pro hobbyist opinions, comments and statements on the meter:
First off, this meter is SOLID. The body has NO give in it at all. Even with the screws removed. The external quality alone is VERY VERY nice in your hands. The rotary knob has a nice feel to it. It feels great when it snaps into the off position. Unlike Aurora my meter came with both an English and a chinese manual (two seperate manuals). My meter has the same modified board that Teknotronix shows. C41 and C42 are moved down closer to the slot (and out from under the resistor array). The resistor array is now vertial and soldered in properly. The changed layout of the capacitorson the side. Now only one piggy back capacitor at C9a. The rest are all normal. Silkscreen has been modified to better match the current part selection (no huge circles around CW1 and CW2). I have no clue how to find the build date.  Honestly, I am supper happy with this. This meter will serve my needs PERFECTLY! It really is kinda overkill for any hobbyist. 8)

I have to agree on all those points. It's very nice for the money.

The build date can be found on a little card inside the manuals.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on January 29, 2012, 12:06:15 am
Mine has the same build date as yours. Oct. 27, 2011. That must be the most recent batch from that factory (or the most recent one currently in circulation).

And I agree, hands down a great meter for how little I spent! Thanks to dave for his review on the 61D and the comments on here for convincing me this was a great quality meter for the <$50 price range.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 29, 2012, 12:15:07 am
Some nicer tear down shots :)

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on January 29, 2012, 01:45:37 am
I think it is easy to say that the UT61E is a good buy, possibly one of the better deals that are available.

UNI-T must have different designers. Some have a clue, and some don't. I would not buy a UT71E again, but I most certainly would buy a UT61E.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 29, 2012, 02:21:48 am

You should drive the backlight leds with transistors. It will safer than old hack.

(http://img692.imageshack.us/img692/7282/dmm.png)
Taken from UT60E dmm schematic (http://320volt.com/wp-content/uploads/2011/05/Unit-UT60E-UT60E-schema-UT60E-circuit-fs9721lp3.gif).

In this configuration, couldn't the same protection be achieved by only using a single NPN rather than the complementary config shown here?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: plunger on January 29, 2012, 03:35:25 am
Fluke leads with 4mm shrouded plugs will work fine....thankfully meter leads tend to follow an industry standard these days.

I did end up getting a Fluke TL81A set. So far so good.

(http://img806.imageshack.us/img806/8746/flukebox.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Bored@Work on January 29, 2012, 08:31:05 am
UNI-T must have different designers. Some have a clue, and some don't. I would not buy a UT71E again, but I most certainly would buy a UT61E.

Now imagine what happens if the next revision of the 61 happens to be done by the 71 designer. Then you start to get an idea why people keep recommending "overpriced" brands like Fluke. It is less of a gamble.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on January 29, 2012, 08:37:01 am
UNI-T must have different designers. Some have a clue, and some don't. I would not buy a UT71E again, but I most certainly would buy a UT61E.

Now imagine what happens if the next revision of the 61 happens to be done by the 71 designer. Then you start to get an idea why people keep recommending "overpriced" brands like Fluke. It is less of a gamble.

You are right. However sometimes people are limited to a budget and just have to make do with the best at a certain price point.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on February 03, 2012, 06:58:31 am
Deal is back on after I applied for a price comparison a few days ago. If you find a cheaper price on something and submit it to them, they update it a few days later :)

Use code DDVALENTINE to get another $10 off


http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e-currency-AUD.html (http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e-currency-AUD.html)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: vk6hdx on February 03, 2012, 07:48:44 am
Deal is back on after I applied for a price comparison a few days ago. If you find a cheaper price on something and submit it to them, they update it a few days later :)

Use code DDVALENTINE to get another $10 off


http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e-currency-AUD.html (http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e-currency-AUD.html)

Good to see, It was a few dollars cheaper when I ordered it (still waiting for it to arrive).  I think it may have been 40% off "RRP" last time. Still looks like a good deal though.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on February 03, 2012, 10:40:55 am
Deal has now ended :(
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on February 03, 2012, 03:28:17 pm

It is 59.20$ on dealextreme.
http://www.dealextreme.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306 (http://www.dealextreme.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306)

BTW I found the UT61E schematic.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on February 03, 2012, 03:53:06 pm

It is 59.20$ on dealextreme.
http://www.dealextreme.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306 (http://www.dealextreme.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306)

BTW I found the UT61E schematic.
Very nice man!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on February 03, 2012, 04:40:35 pm

It is 59.20$ on dealextreme.
http://www.dealextreme.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306 (http://www.dealextreme.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306)

BTW I found the UT61E schematic.


Nice! Great finds!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on February 03, 2012, 07:14:43 pm
I suggest 409shop.
My first UT61E is from 409shop they are fast.
My dinodirect order is still on the way.

59.00$. Lowest price that I can found.  :D
http://www.409shop.com/409shop_product.php?id=103872 (http://www.409shop.com/409shop_product.php?id=103872)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on February 04, 2012, 06:52:08 pm
Just noticed that DinoDirect has a pricematch option. It could be possible to get the meter for $49. Use the pricematch ot get it down to $59, then use the DDValentine coupon code mentioned.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ElectroElvis on February 04, 2012, 10:21:42 pm
Today i ordered Uni-T UT71D for 149€ it should come in comming week. IT is from german shop PinSonne Elektronik. After long consideration i decidet for it since price/performance/features it is the best i could find here in EU.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on February 06, 2012, 01:06:02 am
As an update, because I was bored. I decided to do some resistance and capacitance measurements. I have some 0.1% metal film (or metal foil they use different names in different places) resistors from KOASpeer. I decided to test their resistance. The ones tested were either 1/3W or 1/4W resistors, though I did have 1/2W 0.1% resistors for 3 of the values. I did a spot check on these 1.2W resistors and they fell exactly in line with the values recoreded for the lower wattage varieties.

33.2K ohm
So actual value can range from 33.17K to 33.23K ohms.
The meters rated accuracy in this range is +/-0.5%. Which is a range of 33.03K to 33.37K
Resistor 1 reading:    33.09K
Resistor 2 reading:    33.09K
Resistor 3 reading:    33.09K
Resistor 4 reading:    33.08K
Resistor 5 reading:    33.09K
Resistor 6 reading:    33.10K
Resistor 7 reading:    33.09K
Resistor 8 reading:    33.08K
Resistor 9 reading:    33.09K
Resistor 10 reading:  33.09K
This gives an average reading of 33.089K which is (assuming the resistors are 33.2K) -0.334%. Which is well within the listed accuracy of the meter. Even assuming the worse case scenario of ALL of the resistor being 33.23K, the error is just -0.434%. The precision of both the meter and the resistors is surpisingly good too.

Next up is a 33.0K resistor.
The resistors would fall within the range of 32.967K to 33.033K
0.5% rated meter accuracy means the resistors should fall within 32.835K to 33.165K
Resistor 1: 32.89K
Resistor 2: 32.90K
Resistor 3: 32.90K
Resistor 4: 32.90K
Resistor 5: 32.90K
Resistor 6: 32.90K
Resistor 7: 32.89K
Resistor 8: 32.89K
This gives an average reading of 32.8975K which is (assuming the resistors are 33.2K) an error of -0.311%. Which is well within the listed accuracy of the meter. Even assuming the worse case scenario of ALL of the resistor being 33.033K, the error is just -0.410%. Once again the precision of the meter AND the resistors is quite good.

Next one is a 2K resistor:
The resistors would fall within the range of 1.998K to 2.002K
0.5% rated meter accuracy means the resistors should fall within 1.990K to 2.010K
Resistor 1 reading:    1.9947K
Resistor 2 reading:    1.9950K
Resistor 3 reading:    1.9948K
Resistor 4 reading:    1.9946K
Resistor 5 reading:    1.9951K
Resistor 6 reading:    1.9949K
Resistor 7 reading:    1.9949K
Resistor 8 reading:    1.9948K
Resistor 9 reading:    1.9946K
Resistor 10 reading:  1.9947K
This gives an average reading of 1.9948K which is (assuming the resistors are 2.0K) an error of -0.2595%. Which is well within the listed accuracy of the meter. Even assuming the worse case scenario of ALL of the resistor being 2.002K, the error is just -0.3591%. Once again the precision of the meter AND the resistors is quite good.

Next up are some 220K resistors. This is interesting because it falls on the edge of two ranges. 220Kohm which has a +/- 0.5% accuracy and 2.2Mohm which has a +/- 0.8% accuracy. I will list the 220Kohm range readings first then the 2.2Mohm range readings for the same resistor in parentheses following.
The resistors would fall within the range of 219.78K to 220.22K
0.5% rated meter accuracy for the 220Kohm  means the resistors should fall within 218.90K to 221.10K
0.8% rated meter accuracy for the 2.2Mohm range means the resistors should fall within 0.21824M to 0.22175M
Resistor 1: 219.67K (0.2192M)
Resistor 2: 219.69K (0.2193M)
Resistor 3: 219.68K (0.2193M)
Resistor 4: 219.68K (0.2193M)
Resistor 5: 219.68K (0.2192M)
Resistor 6: 219.65K (0.2192M)
Resistor 7: 219.67K (0.2192M)
Resistor 8: 219.68K (0.2192M)
Resistor 9: 219.69K (0.2192M)
Resistor 10: 219.68K (0.2192M)
This gives an average reading of 219.68K(0.21923M) which is, assuming the resistors are 220K(0.220M), an error of -0.147%(-0.350%). Which is well within the listed accuracy of the meter. Even assuming the worse case scenario of ALL of the resistor being 220.22K (0.2202M), the error is just -0.247%(-0.4495%). While clearly the 220k range appears to have better accuracy, the 2.2Mohm range still falls within the accuracy listed for the 220K range, which is better than its own.

In summary,  the meter appeared to do better than its rated accuracy which is what you would hope for something fresh from the factory.

Next up its capacitance time. To be honest I am not sure how to handle the errors of the capacitors. Often their listed range is larger than the range of the meter. My guess is just treat them as their nominal value and roll with it. For the sake of honesty I include the worst case scenario value as well.

First up are some Panasonic ECG Stacked Metal Film capacitors. They are rated 100V and 0.1uF +/-5%. The meter is rated at +/-3% in this range. The meter reads in nF in this range so the values should center around 100nF
The values for capacitance could range 0.95uF to 1.05uF
The meter should read 97.00nF to 103.00nF or a .06uF range.
Capacitor 1: 99.20nF
Capacitor 2: 101.17nF
Capacitor 3: 101.22nF
Capacitor 4: 99.27nF
Capacitor 5: 99.99nF
Capacitor 6: 100.36nF
Capacitor 7: 101.68nF
Capacitor 8: 99.28nF
Capacitor 9: 101.06nF
Capacitor 10: 99.66nF
THis gives an average value of 100.289nF which is an error of 0.289% from the expected value. In a worse case scenario where all were 105nF, the error becomes -4.48%. This is still within the error range of the capacitors themselves. So the meter does well.

Next up are some enormous UnitedChemicon 100V 2200uF caps. These things are 50mm long and 20mm wide. So 0.86 inches wide and about 2 inches tall. The meter uses the 2.2 mF (millifarad) range, which is the last one which is makes an accuracy claim for. It claims 4% accuracy.
These like most electrolytics have a +/- 20% rating.
Capacitor 1: 2.1790mF
Capacitor 2: 2.1764mF
Capacitor 3: 2.1758mF
Capacitor 4: 2.1787mF
Capacitor 5: 2.1756mF
THis gives an average value of 2.1771mF which is an error of 1.041% from the expected value. In a worse case scenario of an extreme 2.64mF, the error becomes -17.53%. This is still within the error range of the capacitors themselves. So the meter does well.

Lastly, I have some ESC (or SC) brand crap capacitors rated at 25V 120uF. These are the type of caps you expect to find spewing their guts everywhere in a PSU or in the VRM of a motherboard. I can't find out anything about them but my guess is like other cheap/basic capacitors they are rated at 20%.
Capacitor 1: 126.70uF
Capacitor 2: 127.00uF
Capacitor 3: 125.15uF
Capacitor 4: 128.28uF
Capacitor 5: 126.16uF
Capacitor 6: 127.01uF
Capacitor 7: 127.23uF
Capacitor 8: 129.54uF
Capacitor 9: 126.44uF
This gives an average value of 127.06uF which gives an error of 5.88%. The worst case scenario error is 32.35%. I really believe because of the suspect nature of these caps. The readings are fine, but the error falls with the caps themselves. If you notice they don't have nearly as precise values as the rest of the quality components I have measured. The massive 2200uF cap was consistant into the third digit, where these vary wildly.

So in summary, it seems that the meter is definitely capable of meeting its specified accuracy.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on February 06, 2012, 09:33:02 am
Nice work  :)

Its good to know that the meter is pretty accurate, in line with its specifications  :)  Where electrolytic capacitors are concerned I have ways considered their actual values to very variable so ballpark with low ESR is good enough for me. Its interesting to see the variance of value in the lower quality capacitors when compared to better parts.

Many thanks for taking the time to do the tests. For a long time I have used some 1% silver mica capacitors and 0.01% precision resistors (Ex 1980's Solartron 19" rack mount multimeter) to test my meters accuracy. They are very old parts now so it is time for me to source some replacements.

Aurora
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on February 06, 2012, 09:41:39 pm
Nice work  :)

Its good to know that the meter is pretty accurate, in line with its specifications  :)  Where electrolytic capacitors are concerned I have ways considered their actual values to very variable so ballpark with low ESR is good enough for me. Its interesting to see the variance of value in the lower quality capacitors when compared to better parts.

Many thanks for taking the time to do the tests. For a long time I have used some 1% silver mica capacitors and 0.01% precision resistors (Ex 1980's Solartron 19" rack mount multimeter) to test my meters accuracy. They are very old parts now so it is time for me to source some replacements.

Aurora

0.01% resistors would have been nice. Same with the 1% caps.

I was happy to see the device was well within spec as well. Very happy. All the better for sub-$50
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on February 06, 2012, 10:36:17 pm
My 0.01% resistors are pretty old so can't really be trusted now. They read right on my Fluke 87 III though so thats good enough for me  :)

They are HUGE black tubular things encased in black enamel, and mesuring from 15mm to 40mm in length and 10mm to 20mm in diameter ! Very odd looking components, fitted with solder tags and not wire ends. I also salvaged a Weston Cell from the same Solartron meter. The meter was a lab spec unit so had the Weston cell for self calaibration purposes. The cell is still functional but has reached the end of its useful life. You can predict the ageing of the cell in -mV per year quite accurately. My cell has reached the lowest p.d. acceptable for a reliable Weston Cell reference but it is still useful to check high impedance meters for basic accuracy.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on February 07, 2012, 04:59:48 am
My 0.01% resistors are pretty old so can't really be trusted now. They read right on my Fluke 87 III though so thats good enough for me  :)

They are HUGE black tubular things encased in black enamel, and mesuring from 15mm to 40mm in length and 10mm to 20mm in diameter ! Very odd looking components, fitted with solder tags and not wire ends. I also salvaged a Weston Cell from the same Solartron meter. The meter was a lab spec unit so had the Weston cell for self calaibration purposes. The cell is still functional but has reached the end of its useful life. You can predict the ageing of the cell in -mV per year quite accurately. My cell has reached the lowest p.d. acceptable for a reliable Weston Cell reference but it is still useful to check high impedance meters for basic accuracy.

Yay, mercury cadmium salts. Otherwise known as breakfast. :P Its funny those things are such a good standard but if someone tried bring up that idea today. Everyone would look at them as if they had a third head. You want to put liquid mercury and mercury salts in a cell with what? Cadmium salts too! I should know. I get that look all the time when I talk about making the various cadmium compounds that I make.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: vk6hdx on February 14, 2012, 04:28:22 am
I finally got mine after 6 weeks ago ordering it from DinoDirect.  ::)

All seems good so far, though the box was a little bashed up from the postage.  Build date is 18th November 2011.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on February 16, 2012, 06:14:36 pm
Hello i am new to multimeters and bought this product too from Dinodirect. I am using it for low energy DC circuits such as measuring currents (0.005A to 3.000A) in high power LED handheld flashlights (0.8 - 4.3V operating voltage).
I think the manual is totally lacking. I still dont understand much of the functionality of the multimeter, for example what the "PEAK"-button is good for. If anyone knows a detailed step by step user-guide or tutorial with all sorts of examples, application cases and long explanations and descriptions of all the functions and FAQ's (not the poor documentation manual) for the UT61 series, please let me know.

i have basic knowledge of electronics, that's not the problem. it's the product. it doesnt come with an extensive user-guide which explains the product and its functions in detail as i would have expected. the manual is a joke.

but maybe i shouldnt complain. i paid US$ 30 for it only on Dinodirect with some additional discount coupons.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on February 16, 2012, 06:48:29 pm
Try some Fluke or Agilent user guides for multimeters with similar functions. All multimeters are essentially the same once you've figured out which buttons to press. There may also be appnotes out there that tell you how to use certain advanced functions. Some practical electronics books, like practical electronics for inventors, may also explain some of the basics, like measuring current, voltage and resistance.

Don't expect great documentation from vendors like Uni-T. I don't think I've seen one good manual from them. I'm not a big fan of Rigol's documentation, either. This is one area where the more expensive manufacturers like Fluke and Agilent tend to shine. Paying someone to produce good documentation costs money, and this is clearly one area where Uni-T skimps on.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on February 16, 2012, 07:09:17 pm
thanks, will do so. Will also post my other questions in the Beginners section. For our records i found the following picture on the google:
(http://flodins.info/foto/uni-t/DSCF7656.JPG)

and i dont know how to activate, for example the MAX MIN,
and what the other symbols mean (or when they are supposed to show).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on February 19, 2012, 11:31:35 pm
Would anyone know why my meter would suddenly start floating the value in the ohms range at about 120-190 MOhms? It's happening with either the leads in or out. I now have 2 of these meters and only one is doing it. Anyone else have this happening on their 61E?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on February 19, 2012, 11:45:59 pm
Leakage due to contamination, like flux residue on the PCB, which can decrease in resistance after absorbing moisture? This is just a guess.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on February 20, 2012, 12:00:31 am
dinoboy, they use the same pcb and lcd screen for the UT-61 A, B,C,D, E multimeters in the series ... the functions are simply not there... for example the EF in triangle stands for electric field testing (when the meter detects wire in the walls or current in the wall sockets etc) and there's no sensor/antenna inside the meter for that, but the 61A has it.

See the manual, page 11 and 12: http://www.uni-trend.com/manual2/UT61English.pdf (http://www.uni-trend.com/manual2/UT61English.pdf)

EF is in 61A
the icon in the corner is sleep mode (again 61A and maybe others)
MAX / MIN is in several models (a,b,c,d) 
etc
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teknotronix on February 20, 2012, 05:05:05 am
Leakage due to contamination, like flux residue on the PCB, which can decrease in resistance after absorbing moisture? This is just a guess.

Bingo! Cleaned up a few parts of the PCB with circuit board cleaner and she is working fine now. Thanks :D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 21, 2012, 07:14:56 pm
Nice meter ! placing an order soon  ;D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on February 22, 2012, 03:35:32 pm
thanks.
while i still dont understand/know all the buttons of the meter and how to employ them favourably (guide, strategy, examples, application, anti-examples) i have a more urgent question:

Why do i get really different readings for current when i switch from "A" to "mA/microA" (in parentheses)?

For example:
Eneloop AAA @1.47V   
0.130A (155.13mA)
0.015A (24.37mA)

Eneloop AAA @1.05V   
0.419A (77.72mA)
0.027A (60.63mA)

Varta NiMH @1.47V   
0.136A (146.35mA)
0.015A (24.29mA)

I could tell by visual inspection that the voltage drop in the 61E must be higher when i switch to the "mA/microA"-setting, because the original resistor in the circuit consumes much less energy (Watts), which means that the values in parentheses must be less accurate (i guess?). Basically i am measuring currents in a flashlight:
http://www.lygte-info.dk/info/Measurement%20UK.html (http://www.lygte-info.dk/info/Measurement%20UK.html)

i am confused.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: cybergibbons on February 22, 2012, 03:55:37 pm
Normally I'd say it was due to the burden voltage and the DUT changing behaviour as it receives a lower voltage.

The shunt resistor on uA will be quite large, and this means as you approach full range, the voltage drop across it will be large. This will lower the voltage available to the DUT, and will reduce the current. This is especially noticeable on low voltage semiconductor devices where they will just cease to operate and consume little to no current.

However, your readings look odd. For some reason they are higher in one case and lower in another...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on February 22, 2012, 06:22:49 pm
I think this flashlight contains a DC-DC converter to supply the LED with a constant current, regardless of the cell voltage. By dropping extra voltage over the shunt resistor, the voltage to the DC-DC converter is decreased, so the duty cycle (and therefore current draw) is increased to compensate for the lower voltage. The manual should specify burden voltage (either at max current or in V/A) for the different current ranges.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on February 23, 2012, 10:03:26 pm
Thanks for your comments. Yes, it is a regulated flashlight (http://lygte-info.dk/review/Review%20Klarus%20Mi%20X6%20UK.html) for constant light output.

I am thinking, what good is a "89$"-worth DMM if it influences the duty cycle in such a way that i get different readings (almost by factor 2x) in the A vs. the mA range, without a warning? And i am still wondering which reading is correcter than the other..  ::)

Eneloop AAA @1.05V   
0.419A (77.72mA)
0.027A (60.63mA)
oops that was my error. i think that 0.419A are beyond the range of the mA-setting.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on February 23, 2012, 10:51:36 pm
Yes, the 419mA vs 77mA is strange, maybe the regulator switched to a lower current because it was unable to maintain the higher current? Did you notice a significant difference in light output? See Dave's page about the µCurrent (http://www.alternatezone.com/electronics/ucurrent/), and the Silicon Chip article linked from that page, for more information about the effect of burden voltage.

Driven from a constant current source (eg. a lab supply in constant current mode), the lowest range including the measured value should be the most accurate, so for values < 400 mA, the 400 mA range should be more accurate than the 10 A range. The 10 A range will have a lower burden voltage, however, so for sources sensitive to voltage changes, especially a regulator that might drop out or shut down if the voltage gets to low, it may be superior. This is where higher resolution and accuracy sometimes comes in handy. This is essentially also what Dave's µCurrent does: use a lower value shunt resistor and amplify the signal to compensate.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on February 24, 2012, 11:08:45 am
Yes, the 419mA vs 77mA is strange, maybe the regulator switched to a lower current because it was unable to maintain the higher current? Did you notice a significant difference in light output? See Dave's page about the µCurrent (http://www.alternatezone.com/electronics/ucurrent/), and the Silicon Chip article linked from that page, for more information about the effect of burden voltage.
Thanks, will do the reading on burden voltage!

And yes, there was significant difference in light output: When i was in the mA-setting, basically i could not get the light to shine bright in Med-mode anymore. The light's mode sequence is Medium-Low-High, and i was interested in measuring the current in Low-mode. Instead of an DMM error message (Out Of Range) i get low light output when i activate the light (starts in Med-mode), and when i switch to Low-mode the light output is as low.

In fact, the light on Low-mode was dimmer too in the mA-setting compared with the A-setting!

David Jones did the same kind of measurements on his (equally little sized) torch:
h t t p://www.youtube.com/watch?v=0DqHicC6QL4&t=7m15s
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on February 27, 2012, 04:03:45 pm
Burden voltage . If you don't know that , that's sad .
Even high end fluke's and vulnerable to aforementioned problem .
okay thanks everybody. i have read the uCurrent article and watched Dave's video. It basically says that my UT61E (and also high-end Flukes) doesnt measure the milicurrent in the "mA/uA"-setting accurately if i dont pay 59.95$ for Dave's product

:D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on February 27, 2012, 09:08:31 pm
You should look beyond the marketing crap and focus on the technical stuff ;). Not all circuits are as sensitive to changes of voltages. Assume a 7805 linear regulator, which works by dissipating any excess voltage above 5 V. As long as you keep it above 7 V or so at moderate currents, current draw should be almost constant. So a 7805 fed from a 9 V source should have no problem with 1V of burden voltage.

The other extreme is a regulator dropping out of regulation or to a lower current level, like in your example. If you use a variable voltage source as power supply, you can partly compensate for the burden voltage by feeding your circuit a higher voltage.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Tangent_Tracker on February 28, 2012, 04:31:47 pm
Today i ordered Uni-T UT71D for 149€ it should come in comming week. IT is from german shop PinSonne Elektronik. After long consideration i decidet for it since price/performance/features it is the best i could find here in EU.
Will you please be good enough to perform a little review of this meter? There is one on youtube but I don't really think it is all that great tbh...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: cybergibbons on February 28, 2012, 08:08:20 pm
He thought it was crap and returned it, though the specific unit he had obviously had faults.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Vredstein on March 01, 2012, 11:32:31 pm
They've changed the layout a bit in the version I got today. Added the C2* component and some other bits.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on March 17, 2012, 07:49:30 pm
FYI, the product was reviewed by fellow member HKJ on the flashlight forums:

http://budgetlightforum.com/node/8642 (http://budgetlightforum.com/node/8642)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: LEECH666 on May 02, 2012, 10:33:53 pm
Could some of you UT-61E owner tell me if it is normal that the mV (DC) range shows O.L. with nothing attached to the jacks? My DMM does that and I find this kinda weird. The mV (AC) range doesn't do this and reads close to 1.7 mV (once it has settled).

The printing on the Ampere jacks is confusing me too. It says "EACH 15min MAX 10sec" ... ???

So which one is true? 15 minutes or 10 seconds?

Cheers,
Florian
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Spawn on May 02, 2012, 10:37:03 pm
The printing on the Ampere jacks is confusing me too. It says "EACH 15min MAX 10sec" ... ???

So which one is true? 15 minutes or 10 seconds?

You can measure  the max current allowed only every 15 minutes for 10 seconds long before shunt cools down.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on May 02, 2012, 10:47:08 pm
Could some of you UT-61E owner tell me if it is normal that the mV (DC) range shows O.L. with nothing attached to the jacks? My DMM does that and I find this kinda weird. The mV (AC) range doesn't do this and reads close to 1.7 mV (once it has settled).

The printing on the Ampere jacks is confusing me too. It says "EACH 15min MAX 10sec" ... ???

So which one is true? 15 minutes or 10 seconds?

Cheers,
Florian

Yes, the mV will go to OL with the leads in the air. Tested it right now with my 61E. The mV setting has no autorange so it will go by default to OL.

EACH 15min MAX 10sec   =  perform a measurement for a maximum of 10 seconds, then wait about 15 minutes for the shunt to cool down.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: LEECH666 on May 02, 2012, 10:57:46 pm
Yes, the mV will go to OL with the leads in the air. Tested it right now with my 61E. The mV setting has no autorange so it will go by default to OL.

Thank you, so my meter is not broken. I'm still wondering why it does that and why it's different for the mV AC range.

EACH 15min MAX 10sec   =  perform a measurement for a maximum of 10 seconds, then wait about 15 minutes for the shunt to cool down.

Thanks for explaining, it probably is also written down in the handbook, but I figured I asked this too since I was about to post the other question anyway.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on May 03, 2012, 12:58:19 am
Yes, the mV will go to OL with the leads in the air. Tested it right now with my 61E. The mV setting has no autorange so it will go by default to OL.

Thank you, so my meter is not broken. I'm still wondering why it does that and why it's different for the mV AC range.

Put the meter into the 2VDC range and turn min/max on. Now rub a plastic bag over the case over the input terminals.

Remember, the mV range maxes out at 220mV.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: LEECH666 on May 03, 2012, 12:37:22 pm
I wasn't aware that the mV range is that sensitive to static charges. Thanks for clearing that up.

Florian
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on May 03, 2012, 05:32:10 pm
Input impedance in the 220 mV range is specced as > 3 Gohm, input impedance in the higher DCV ranges is around 10 Mohm. It does not take a lot of current (think induction) to produce 220 mV in a 3 Gohm load.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: flodins on May 19, 2012, 11:23:44 am
Here is my review whitch from was foto on previous page

http://translate.google.pl/translate?hl=pl&sl=pl&tl=en&u=http%3A%2F%2Fflodins.info%2Fmoim-zdaniem%2F81-multimetr-uni-t-ut61e (http://translate.google.pl/translate?hl=pl&sl=pl&tl=en&u=http%3A%2F%2Fflodins.info%2Fmoim-zdaniem%2F81-multimetr-uni-t-ut61e)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on May 23, 2012, 04:26:52 pm
Meh ... if i want to take picture i would use my D3100 but this is a rough one since you guys know mostly what's inside but there are differences in this 2011 batch version
(http://i492.photobucket.com/albums/rr283/DarkShadower/IMAG0002.jpg)(http://i492.photobucket.com/albums/rr283/DarkShadower/IMAG0003.jpg)
(http://i492.photobucket.com/albums/rr283/DarkShadower/IMAG0004.jpg)
(http://i492.photobucket.com/albums/rr283/DarkShadower/IMAG0005.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on May 24, 2012, 08:08:13 pm
Meh ... if i want to take picture i would use my D3100 but this is a rough one since you guys know mostly what's inside but there are differences in this 2011 batch version
(http://i492.photobucket.com/albums/rr283/DarkShadower/IMAG0002.jpg)(http://i492.photobucket.com/albums/rr283/DarkShadower/IMAG0003.jpg)
(http://i492.photobucket.com/albums/rr283/DarkShadower/IMAG0004.jpg)
(http://i492.photobucket.com/albums/rr283/DarkShadower/IMAG0005.jpg)

Yeah that looks like the version I got and Tektronix has some Hi-Res pics of on page 8. I think they made some improvements in layout and overall build quality with respect to the board. The resistor network is now soldered in properly, most components match the silk screen, etc.

I must say that after having it owned it for a few months I am still incredibly happy with this multimeter. This meter is truly perfect for the serious hobbyist. I really think its one of the best, if not the best, in the price range. It's very hard to find something this well put togther and still have it hit the sub-$60 price point. I really think they hit the low end pretty well. The UT10A at  $12.70 seems to be a capable cheap pocket meter review on here by Lightages (https://www.eevblog.com/forum/product-reviews-photos-and-discussion/uni-t-ut10a-review/)). The UT33D at a similar price adds features (loses autoranging though). Then the UT61E is also great. it seems like they are great at the low end stuff not so much at the high end. Heh.


Oh yeah, I read somewhere that the biggest model change in the 2011 versions that they use a higher precision resistor/divider network.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on May 24, 2012, 11:58:20 pm
My pics are pretty bad because lighting is non-existant on my glass table ... haven't taken my hi-res cam out yet
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Milton on July 04, 2012, 10:29:25 am
UNI-T UT61E

USB Mod and Backlight Mod (website in Russian)
http://we.easyelectronics.ru/ACE/dorabotka-napilnikom-multimetra-ut61e.html (http://we.easyelectronics.ru/ACE/dorabotka-napilnikom-multimetra-ut61e.html)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on July 04, 2012, 03:38:18 pm
UNI-T UT61E

USB Mod and Backlight Mod (website in Russian)
http://we.easyelectronics.ru/ACE/dorabotka-napilnikom-multimetra-ut61e.html (http://we.easyelectronics.ru/ACE/dorabotka-napilnikom-multimetra-ut61e.html)

Backlight mod ... not gonna lose a epic hold for that
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: LEECH666 on July 04, 2012, 08:05:24 pm
I don't think this is the same backlight mod the other guy showed us here on the forums. From what I get from Google Translate it uses an ATtiny13 µC to implement an auto off function too.

http://translate.google.de/translate?sl=auto&tl=en&js=n&prev=_t&hl=de&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwe.easyelectronics.ru%2FACE%2Fdorabotka-napilnikom-multimetra-ut61e.html&act=url (http://translate.google.de/translate?sl=auto&tl=en&js=n&prev=_t&hl=de&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwe.easyelectronics.ru%2FACE%2Fdorabotka-napilnikom-multimetra-ut61e.html&act=url)

Shouldn't it be relatively easy to write a software for the µC that meassures how long the button was pressed and then trigger the respective functions (hold, backlight on/off, display freeze hold) accordingly?

Maybe someone who speaks Russian can translate that article, so that we can make more sense of it. I am not sure that you lose the Hold function.

Florian
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: nukie on July 05, 2012, 02:31:34 am
The 61 series is applauded for its excellent linearity.

tapatalk
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on July 08, 2012, 04:22:38 pm
By looking the spec sheet I noticed that

Capacitance range is(22nF/220nF/2.2mF/22mF/220mF/2.2mF/22mF/220mF) does it means that I can't measure 4000uF electrolytic capacitors?

On the other hand Ut61C can (40nF/400nF/4mF/40mF400mF/4000mF)

So is that UT61C has larger range than UT61E ?

Specs-Ut-61C----http://www.uni-trend.com/UT61C.html
 Ut-61E-----http://www.uni-trend.com/UT61E.html


Noobs question  :-[
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: cuban8 on July 08, 2012, 05:07:31 pm
FYI- 4000uF is 4mF.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on July 08, 2012, 06:32:50 pm
By looking the spec sheet I noticed that

Capacitance range is(22nF/220nF/2.2mF/22mF/220mF/2.2mF/22mF/220mF) does it means that I can't measure 4000uF electrolytic capacitors?

On the other hand Ut61C can (40nF/400nF/4mF/40mF400mF/4000mF)

So is that UT61C has larger range than UT61E ?

Specs-Ut-61C----http://www.uni-trend.com/UT61C.html
 Ut-61E-----http://www.uni-trend.com/UT61E.html


Noobs question  :-[

Read the PDF properly, they quote 4000uF
As for the UT61E, of course it's not so weak it's written all over on this forum that it's got the most substantial range of the 60$ meter range. And i own one definitely
220mF ... that's 220,000uF at 2% accuracy ( chipset, UNI-T didn't do a test )
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on July 11, 2012, 07:29:36 pm
By looking the spec sheet I noticed that

Capacitance range is(22nF/220nF/2.2mF/22mF/220mF/2.2mF/22mF/220mF) does it means that I can't measure 4000uF electrolytic capacitors?

On the other hand Ut61C can (40nF/400nF/4mF/40mF400mF/4000mF)

So is that UT61C has larger range than UT61E ?

Specs-Ut-61C----http://www.uni-trend.com/UT61C.html
 Ut-61E-----http://www.uni-trend.com/UT61E.html


Noobs question  :-[

Read the PDF properly, they quote 4000uF
As for the UT61E, of course it's not so weak it's written all over on this forum that it's got the most substantial range of the 60$ meter range. And i own one definitely
220mF ... that's 220,000uF at 2% accuracy ( chipset, UNI-T didn't do a test )

Good eye there Dave.

The Uni-T website uses the wrong SI abbreviation for the capacitor series.
The website says 40nF/400nF/4mF/40mF400mF/4000mF for the 61C but it SHOULD read 40nF/400nF/4uF/40uF/400uF/4000uF.
Interestingly, the 61E website says: 22nF/220nF/2.2mF/22mF/220mF/2.2mF/22mF/220mF but the mF that should be uF have a different m (it has serifs on it, while the one for mF is sans serif).

Either way. the 61E is significantly better than the 61C.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on July 12, 2012, 04:06:27 pm
Sometimes to read their manuals you really have to anticipate what they wanted to write in the first place.
But yeah, the UT61E only costs a slight bit more plus i'd rather have a proper dedicated temp. meter ITFP
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on July 16, 2012, 08:12:19 pm
My new teardown pictures are in here. (http://sigrok.org/wiki/UNI-T_UT61E#Photos)

I do this new teardown for the sigrok project. (http://sigrok.org)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on July 17, 2012, 09:52:58 pm
[...]

So do we all agree that the UT61E is a great, accurate DMM, especially for its price? As most people in this thread i bought mine from Dinodirect (no shilling haha) and thanks to the discount code, dinopoints and giftcards etc i paid only like 31$ (please no envy!! ;) ). since its acquisition i use it every other day to measure battery voltages (NiMH, LiIon) or continuous currents in flashlights (with the UT61E serial connection PC cable). i already had to replace the 9V UNI-T battery!!

The only measurement flaw it has is its high burden voltage -- but this is a rather common problem with any cheap or expensive DMM afaik.

i like the DMM a lot, it costs now ~59$ on DX.com (=double the price i had paid hehe). Because of a missing comprehensive user guide, i still dont understand the proper usage of all functions (e.g. the Min-Max buttons with several examples) but i can live with it.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on July 18, 2012, 10:08:00 am
Of course it's a excellent meter for it's price.
It's specs are quoted at 1 year and is next-to-next with the 87v
Always remember: You get what you pay for, if you don't expect absolute safety of course you know you won't be getting it
No point calling the 61E a terrible meter just because it's doesn't have those oh so lovely 20kA huge hrc fuses
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on July 18, 2012, 12:42:37 pm
It's specs are quoted at 1 year and is
Hi, why are you mentioning time ("1 year")? What role does time play in the discussion of a multimeter? My PC is 10 years old and it works like ever! :D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on July 18, 2012, 01:04:21 pm
It's specs are quoted at 1 year and is
Hi, why are you mentioning time ("1 year")? What role does time play in the discussion of a multimeter? My PC is 10 years old and it works like ever! :D

Because that's what they said. Minimum guaranteed 1 year stability just like any proper meter is quoted at 1 year stability
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on July 20, 2012, 12:42:03 pm
Because that's what they said. Minimum guaranteed 1 year stability just like any proper meter is quoted at 1 year stability

so after 1 year we would have to recalibrate the thing?
Are FLUKE's the same, with only 1 year guaranteed stability?
Sounds poor :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on July 20, 2012, 03:11:43 pm
Generally after a year the short term drift and thermal shift from assembly have levelled out to only give the long term drift as the dominant effect over temperature caused drift. You calibrate after a year to get the best accuracy, as a new reference or a newly soldered unit will have an offset that slowly decays to a long term trend.

It might read 1.0000V initially, and after a year it might read 0.9997V, with the same reference source, which has been powered for years and kept at a constant temperature and certified with a traceable source to a standard volt.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on July 20, 2012, 04:42:40 pm
Carefully characterized DMMs are usually specified for 24h, 90 days and 1 year accuracy, within a certain temperature range. Long term drift is rarely specified, but in good designs (eg. Fluke 87), this can be expected to be close to the 1 year figure, since drift tends to level off with time as SeanB mentions. By far the most drift will be within the first year.

In the case of Uni-T, you'd be lucky if it meets the 1 year spec, all bets are off for long term stability. People with the equipment to test DMM stability are not usually interested in cheap handhelds. Cal labs don't have much data on them either, since people rarely send them in for calibration.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on July 20, 2012, 06:05:46 pm
Carefully characterized DMMs are usually specified for 24h, 90 days and 1 year accuracy, within a certain temperature range. Long term drift is rarely specified, but in good designs (eg. Fluke 87), this can be expected to be close to the 1 year figure, since drift tends to level off with time as SeanB mentions. By far the most drift will be within the first year.

In the case of Uni-T, you'd be lucky if it meets the 1 year spec, all bets are off for long term stability. People with the equipment to test DMM stability are not usually interested in cheap handhelds. Cal labs don't have much data on them either, since people rarely send them in for calibration.

And the calibration probably costs more than the meter
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on July 20, 2012, 06:24:51 pm
Most cal labs would only get a meter in that is rack mounted, though you will find that avionics and military service units send all meters in for calibration, from hand held volt sticks ( yes, even a neon light voltstick will be verified that it is within the specified limits) up to a multimillion avionics test bench ( I drove the van it was in for a month, just to get the 40 year old Citroen van over the 1000km mark while the insides were away for the calibration cycle, otherwise the van did 1km per year) used to do full aircraft ground testing.

The value of calibration is that you can be sure the reading you took last year is the same as the reading you took this year, or that the error is known in both magnitude and polarity. The meter is often the cheapest part of the whole system, the value being in the history.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on July 20, 2012, 08:25:15 pm
Thankx "cuban8" & "DaveXRT" for clearing my doubts  :D.

Some more Qs

1>Are there any the trim-pots needed for calibrating each functions(1 for each) in this multimeter(Ut61-E) ?
     Actually I did it with my cheap multimeter ie; only on Dc volts but other than that there are no other trim-pots to calibrate resistance,Current,Capacitance & etc.           

 2>Say for example one has high quality resistors with 0.1% tolerance & Caps,so setting as its base can it be calibrated as specs of the resistors as a base in(Ut-61E)

3>Suppose there are no trim-pots so what are the ways for calibration with out going to the labs ?

One more thing,What's the differences between these two ?

1>http://www.dinodirect.com/ut61e-modern-digital-multimeters.html?DDID=3520-616 (http://www.dinodirect.com/ut61e-modern-digital-multimeters.html?DDID=3520-616)
2>http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html?DDID=3520-616 (http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html?DDID=3520-616)



Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on July 22, 2012, 10:59:05 pm
dinodirect is just a dropshipper, so two companies might list the same product
Sorry to burst your bubble but calibration as it's calle$ it's not the calibration you are expecting,
it's just using something an order of magnitude more accurate to reference the values on the meter you are "calibrating"/
or using one of those multislope DAC HP/Agilent PSU's to give you the "calibrated" value shown on the certificate
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on July 23, 2012, 07:55:17 am
Thanks all for the explanation of the calibration and timing thing.. I do have reference sources like my Li-Ion rechargeable cells which all terminate at 4.200V from my new charger, the Nitecore Intellicharge i4 (by Sysmax Ind.).

One more thing,What's the differences between these two ?

1>http://www.dinodirect.com/ut61e-modern-digital-multimeters.html?DDID=3520-616 (http://www.dinodirect.com/ut61e-modern-digital-multimeters.html?DDID=3520-616)
2>http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html?DDID=3520-616 (http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html?DDID=3520-616)
I asked in Dinodirect presales chat, and they gave this answer:
(http://img543.imageshack.us/img543/9112/snap641.png)

Hope this helpz!!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on July 23, 2012, 02:58:36 pm
Use a proper reference source.
http://sg.element14.com/jsp/search/productdetail.jsp?sku=1827385 (http://sg.element14.com/jsp/search/productdetail.jsp?sku=1827385)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on July 26, 2012, 01:15:07 am
The meter is back on sale at DinoDirect. Using the cheaper listing of $56.99

Product Link (http://www.dinodirect.com/ut61e-modern-digital-multimeters.html)

Then use the following coupon code to knock off 10%:
cheaper10off

This brings the total down to $51.29 shipped. Not quite the $46 or $49 it was previously but still quite a deal.

If you are a fatwallet member, they offer 5% cashback from dinodirect which would bring the meter back down to its $49 price point.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on July 27, 2012, 09:58:49 am
Its auto range is very fast, but when I measure some large resistance in the Meg range or whatever else a bit jumpy especially when the contact is not absolutely firm, it goes hunting cycles too fast and misses settling. Then I go hit manual mode and its OK. My Fluke 17B is slower but settles always in autorange. Is it just my sample or your 61E works the same guys?
I am happy with 61E's speed & accuracy and resolution in general, does very well with capacitors ref my LCR meter also.  Hitting RANGE again does not return to auto unless selecting some other function on the rotary and returning. Is there a DMM that cycles auto/manual with the dedicated button without need to engage the rotary? My Fluke 17B & Mastech MS8218 do not either.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on July 27, 2012, 12:25:40 pm
Its auto range is very fast, but when I measure some large resistance in the Meg range or whatever else a bit jumpy especially when the contact is not absolutely firm, it goes hunting cycles too fast and misses settling. Then I go hit manual mode and its OK. My Fluke 17B is slower but settles always in autorange. Is it just my sample or your 61E works the same guys?
I am happy with 61E's speed & accuracy and resolution in general, does very well with capacitors ref my LCR meter also.  Hitting RANGE again does not return to auto unless selecting some other function on the rotary and returning. Is there a DMM that cycles auto/manual with the dedicated button without need to engage the rotary? My Fluke 17B & Mastech MS8218 do not either.

Hold the range button, it will return to auto
and, because it's got a crazy resistance range it's expected to go wild with such a range, but apparently mine doesn't jump about when the contact isn't all that good (tested with 1M,3.3M,10M and SMD 100M)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on July 27, 2012, 06:34:21 pm
Thanks, I held the RANGE button and it switched. :) Tried with the high value resistors again and I noticed that when touching with the probe tips it settles, but when holding down through hole resistor leads fitting in the before tip grooves, pressing down almost horizontally on the bench, the range dances much more. If there is a soft mat it locks easily. One nice thing I saw I could do is by PEAK at Pmax it can work as touch hold (for voltage & current). Nice. 8)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on July 28, 2012, 04:13:45 am
You can also use delayed hold by holding the Hold ... Holdception
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: brucers on August 01, 2012, 08:22:56 pm
Thankx "cuban8" & "DaveXRT" for clearing my doubts  :D.

One more thing,What's the differences between these two ?

1>http://www.dinodirect.com/ut61e-modern-digital-multimeters.html?DDID=3520-616 (http://www.dinodirect.com/ut61e-modern-digital-multimeters.html?DDID=3520-616)
2>http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html?DDID=3520-616 (http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html?DDID=3520-616)

One of these is priced at $56.99 and one is priced at $83.99. In the listed specs one says it has a display backlight and one doesn't mention it. And reading the customer reviews on the website, one reviewer says his DOES have a display backlight. Interestingly the one that lists the display backlight in the specs is the cheaper one.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 01, 2012, 10:38:46 pm
Thankx "cuban8" & "DaveXRT" for clearing my doubts  :D.

One more thing,What's the differences between these two ?

1>http://www.dinodirect.com/ut61e-modern-digital-multimeters.html?DDID=3520-616 (http://www.dinodirect.com/ut61e-modern-digital-multimeters.html?DDID=3520-616)
2>http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html?DDID=3520-616 (http://www.dinodirect.com/multimeter-multifunction-digital-uni-t-ut61e.html?DDID=3520-616)

One of these is priced at $56.99 and one is priced at $83.99. In the listed specs one says it has a display backlight and one doesn't mention it. And reading the customer reviews on the website, one reviewer says his DOES have a display backlight. Interestingly the one that lists the display backlight in the specs is the cheaper one.

You can't trust those reviews, they're loaded with bollocks. Prime example:
Quote
You need a special screw driver to get the back open and put the batteries in. I take batteries out after each use and put them in the refrigerator.

It has a single #2 phillips screw for the single 9V battery.

Quote
This is a great little meter. I bought it mainly for the ammeter to test leaky circuits on automotive applications. The meter is just the right size to clip over the battery cable and get a good reading. It has the right range for this application. Much less expensive than another meter I was looking at.

It is not a clamp meter.

Quote
The only real advanatge of this meter was size and the non-contact voltage measurement-which in my case is not a big deal. After purchasing this model I tried out the various functions and was very pleased with its performance. The three best features of this meter are [1] auto ranging (don't buy a meter without it), [2] the large easy to read display and [3] the display back light. This meter is simple to use and has handled anything I've thrown at it with ease.

It does not have non-contact voltage measurement, it does not have a backlight.

Those reviews are not of a UT61E.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: brucers on August 04, 2012, 11:55:43 pm
I have a question about the 'HOLD' function on the  UNI-T UT61E.  Does pressing the "HOLD" button  simply just freeze the display of  your last reading or can you press the "HOLD" button, then take a measurement, and then that measurement will be held?  Thanks in advance for any info. Bruce
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: David_AVD on August 05, 2012, 12:08:19 am
Does pressing the "HOLD" button  simply just freeze the display of  your last reading or can you press the "HOLD" button, then take a measurement, and then that measurement will be held?

I just tried it.  Pressing HOLD during a reading freezes the displayed value.  Pressing it again releases the freeze.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 05, 2012, 12:12:00 am
Does pressing the "HOLD" button  simply just freeze the display of  your last reading or can you press the "HOLD" button, then take a measurement, and then that measurement will be held?

I just tried it.  Pressing HOLD during a reading freezes the displayed value.  Pressing it again releases the freeze.

You can also do a delayed hold. iirc it's a 5 second timer. Just hold the button until it beeps, and take a measurement until it beeps again.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: David_AVD on August 05, 2012, 12:15:48 am
You can also do a delayed hold. iirc it's a 5 second timer. Just hold the button until it beeps, and take a measurement until it beeps again.

Ah, excellent.  Thanks for that.   :)

The manual that came with mine was not English.  I only got it a couple of days ago so haven't tried many of the features yet.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 05, 2012, 12:21:37 am
You can also do a delayed hold. iirc it's a 5 second timer. Just hold the button until it beeps, and take a measurement until it beeps again.

Ah, excellent.  Thanks for that.   :)

The manual that came with mine was not English.  I only got it a couple of days ago so haven't tried many of the features yet.

The manual, such as it is, is available here: http://www.uni-trend.com/manual2/UT61English.pdf (http://www.uni-trend.com/manual2/UT61English.pdf)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: David_AVD on August 05, 2012, 12:28:56 am
Thanks for the manual link.  I see what you mean by "such as it is".  The delayed hold function isn't even mentioned.

Quote
The Hold mode is applicable to all measurement functions.
  • Press HOLD to enter Hold mode; the Meter beeps.
  • Press HOLD again to exit Hold mode; the Meter beeps.
  • In Hold mode, is displayed.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 05, 2012, 12:38:56 am
Thanks for the manual link.  I see what you mean by "such as it is".  The delayed hold function isn't even mentioned.

Quote
The Hold mode is applicable to all measurement functions.
  • Press HOLD to enter Hold mode; the Meter beeps.
  • Press HOLD again to exit Hold mode; the Meter beeps.
  • In Hold mode, is displayed.

The datasheet for the IC contains a lot of useful information: http://www.cyrustek.com.tw/spec/ES51922.pdf (http://www.cyrustek.com.tw/spec/ES51922.pdf)

For example, if you hold the HOLD key while turning the meter on, all display segments will remain lit until you press the HOLD key again.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 05, 2012, 02:27:55 am
The amazing thing is that it actually has a LPF ...
A dual slope ADC ... which again has high speed and high res mode ...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 05, 2012, 02:59:20 am
The amazing thing is that it actually has a LPF ...

Not that it's enabled on the UT61E.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 05, 2012, 03:03:29 am
The amazing thing is that it actually has a LPF ...

Not that it's enabled on the UT61E.

It is ... It's enabled!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 05, 2012, 03:06:17 am
The amazing thing is that it actually has a LPF ...

Not that it's enabled on the UT61E.

It is ... It's enabled!

But you can't access it. FC5 needs to be brought low, the UT61E leaves it floating.

I'm pondering modifying mine to disable the RS232 output unless I actually plug the adapter in. If the trace is accessible I just need to cut it and put a microswitch in..

E: On second thought, I've just seen someone who's done that by adding an IR LED to the RS232 adapter and a phototransistor to the meter. Much neater, don't know what I was thinking.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 08, 2012, 07:49:22 am
UT61E arrived from Dino!
Oh man, the box came intact, unlike what i've seen from DX (Somebody was having a bad day indeed) or it might be because of the shipping methods ...
they changed my shipping to EMS without me having to pay extra
(Looks like the box had a revision ... the plastic tray holding the meter and probes is no longer opaque but a very nice transparent colour)
I should mention, the CD in which my meter came from DX broke into half
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on August 10, 2012, 06:27:37 pm
Thanks, I held the RANGE button and it switched. :) Tried with the high value resistors again and I noticed that when touching with the probe tips it settles, but when holding down through hole resistor leads fitting in the before tip grooves, pressing down almost horizontally on the bench, the range dances much more. If there is a soft mat it locks easily. One nice thing I saw I could do is by PEAK at Pmax it can work as touch hold (for voltage & current). Nice. 8)

Just curious, is this the same salas who is a mod over at DIYAudio? I know kinda weird but just wodering.  ;D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 11, 2012, 03:20:02 am
Hello. I found this thread via Google when I was trying to find more info regarding a pair of UT61E's I bought. I'm actually quite impressed with the meters but the bundled software leaves a lot to be desired. Because I'm a software developer by trade, I decided to write a proper, feature-rich version of the multimeter software. Before you stop reading, I don't plan to charge anything for the software, this is just a hobby of mine. I'll make this software available free for download on my site.

I've got far enough now to be able to sample data properly from the meters. Now I'm implementing the features that I thought would be good to have like.

Ability to monitor multiple meters at once.
Set up triggers based on various criteria (value in range, value rising, value falling, etc)
Triggers can be audible or visual or both. Can even have the sound frequency change as value goes up or down.
Because it'll support multiple meters, having triggers like delta between values changing becomes possible.
also with multiple meters, it'll be possible to measure wattage.
Smoothing of values over variable number of samples, etc.

And of course the usual, gauges, charts, exporting, history, etc.

I'm curious if anybody has any interest in such software or does anyone have any other ideas for features that might be worth implementing?

Tom
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 11, 2012, 03:28:54 am
I'm interested  8)
Add in a better graphing option, the bundled one is pretty hopeless

i was graphing a li-ion charger that was jumping between 4.0 and 4.2V and the graph didn't show anything like that
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: David_AVD on August 11, 2012, 03:30:09 am
Because I'm a software developer by trade, I decided to write a proper, feature-rich version of the multimeter software

Sounds good Tom.  I agree that most of the software supplied with meters, etc is in the poor to useless category and often unstable.  I have a UT61E so would be keen to give it a whirl.   :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 11, 2012, 03:36:44 am
I'll be working on it throughout this week. I'll post up once I have something worth looking at.

I should add that there is one catch though. I typically use projects like these to learn new programming techniques. In this case using the pre-release Visual Studio 2012 and .Net Framework 4.5. Which is not officially out yet. If you're planning to run the software, you'd have to install the "beta" framework from Microsoft site. .Net Framework is currently in RC (Release Candidate) status.

Tom
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: FenderBender on August 11, 2012, 03:39:20 am
Sounds great.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Bored@Work on August 11, 2012, 04:18:12 am
http://www-user.tu-chemnitz.de/~heha/hs_freeware/UNI-T/dmm.zip (http://www-user.tu-chemnitz.de/~heha/hs_freeware/UNI-T/dmm.zip)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 11, 2012, 02:34:54 pm
Ah sweet, thanks for the link. Now at least I can get a compatible model list from it.

Tom
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 15, 2012, 03:39:07 am
Just a quick update on the software.

It's getting there. The logic and UI is around 90% done. Next I'll take on the actual Gauge/Graph displays. I should have a BETA release in few days.

(http://www.alteredrealms.com/wp-content/uploads/2012/08/KaskingoDMM2.png)
(http://www.alteredrealms.com/wp-content/uploads/2012/08/KaskingoDMM.png)


Cheers,

Tom
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: David_AVD on August 15, 2012, 03:41:22 am
Looking good Tom.  Maybe start a new thread and get these posts moved there?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on August 21, 2012, 10:44:41 am
Any luck if the UT61E to the pc with this by rs232 connection

http://www.dealextreme.com/p/wireless-bluetooth-rs232-ttl-transceiver-module-80711 (http://www.dealextreme.com/p/wireless-bluetooth-rs232-ttl-transceiver-module-80711)

'Wireless Bluetooth V2.0 RS232 TTL Transceiver Module'

I am just a electronic enthusiast so spare me if the question is silly.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 21, 2012, 12:09:09 pm
Any luck if the UT61E to the pc with this by rs232 connection

http://www.dealextreme.com/p/wireless-bluetooth-rs232-ttl-transceiver-module-80711 (http://www.dealextreme.com/p/wireless-bluetooth-rs232-ttl-transceiver-module-80711)

'Wireless Bluetooth V2.0 RS232 TTL Transceiver Module'

I am just a electronic enthusiast so spare me if the question is silly.

Probably yes, use one for the PC and one for the meter but the other side is RS232 is also so yes things still need to be converted on USB
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 21, 2012, 12:19:26 pm
Any luck if the UT61E to the pc with this by rs232 connection

http://www.dealextreme.com/p/wireless-bluetooth-rs232-ttl-transceiver-module-80711 (http://www.dealextreme.com/p/wireless-bluetooth-rs232-ttl-transceiver-module-80711)

'Wireless Bluetooth V2.0 RS232 TTL Transceiver Module'

I am just a electronic enthusiast so spare me if the question is silly.

Probably yes, use one for the PC and one for the meter but the other side is RS232 is also so yes things still need to be converted on USB

Why would you use one for the PC? You connect one to the meter, and connect to it with bluetooth. You can't just connect two of those modules to each other.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 21, 2012, 12:47:16 pm
Aw man you're right i forgot. Sorry about that
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on August 23, 2012, 08:33:11 am
So it looks that using the bluetooth module with Ut61e is feasible  :),so if anyone any one tries it plz inform that how did it worked out.

Only thing I will love to see is measuring temp with an auto off feauture
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 23, 2012, 08:41:46 am
Well it's about what you want then.
For me i can't stand APO ... most APO meters i use in school shut off silently after 15mins when i'm doing something
And i can't stand the temperature on the cheaper meters either, UT61B can track in PC with the temp thing
1) No 0.1C resolution, even if the probe is not any better than 5% ... (The last cheaper meter that can do 0.1C and PC is non-existent)
2) No Kelvins unit
3) 1 probe only!
4) No Min/Max/Avg ...

So in the end i wound up for this
http://www.dealextreme.com/p/2-2-lcd-digital-thermometer-handheld-temperature-tester-1-x-9v-6f22-120770 (http://www.dealextreme.com/p/2-2-lcd-digital-thermometer-handheld-temperature-tester-1-x-9v-6f22-120770)
But it's not FR4 anymore :(
Same as this one : http://www.dealextreme.com/p/k-type-digital-industrial-thermometer-with-sensor-50-c-1300-c-7286?item=1936 (http://www.dealextreme.com/p/k-type-digital-industrial-thermometer-with-sensor-50-c-1300-c-7286?item=1936)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 24, 2012, 08:31:02 pm
Version 1 is coming out soon. Anyone interested in doing some Beta testing?

(http://www.alteredrealms.com/wp-content/uploads/2012/08/KaskingoDMM3.png)

Tom
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: David_AVD on August 24, 2012, 09:31:15 pm
Version 1 is coming out soon. Anyone interested in doing some Beta testing?

I can give the software a quick whirl if you like.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on August 24, 2012, 09:39:26 pm
What was that!? UNI-T UT61E freaks out ... [720p,XVID,AVI] (https://www.youtube.com/watch?v=Bt65TZDZMSY#ws)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on August 24, 2012, 10:15:05 pm
I think this video was already posted in this forum already, maybe this very same thread.

If I remember correctly, one of the explanations was that the sides of the probes are somewhat dirty with bits of silicon left from the factory when the silicon was poured into the form and all that. Easily fixed by cleaning the sides of the probes from impurities.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 25, 2012, 01:14:49 am
Version 1 is coming out soon. Anyone interested in doing some Beta testing?

No problem there

@Ivanko
https://www.eevblog.com/forum/general-chat/uni-t-ut61e-freaks-out/msg104612/#msg104612 (https://www.eevblog.com/forum/general-chat/uni-t-ut61e-freaks-out/msg104612/#msg104612)
His metrix "freaked" out too
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 25, 2012, 02:54:33 pm
If you want to take a crack at the DMM program. Please PM me, and I'll send you a download link.

Tom
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: AndyC_772 on August 25, 2012, 03:34:42 pm
What was that!?

Looks as though there are two problems there.

One is certainly that the probes aren't conducting as reliably as they should - whether they're dirty, covered in oxide or whatever. I had a very similar experience with a set of probes from Maplin a few weeks ago, and took them straight back as unfit for purpose. Life is too short for test equipment that doesn't do its job properly.

The other I suspect is down to how the autoranging feature works in the presence of an inductive load. I can see a way in which it could start oscillating, which would prevent the meter from ever reaching a steady state.

Suppose the meter applies a small voltage and tries to measure the current. The coil is inductive, so initially very little current flows. The meter detects this as a high resistance, so switches up to a new range. Meanwhile, the current in the coil is ramping up (V=L dI/dt). The coil current is now too high for the high resistance range, so the meter switches back to a lower resistance range, with a smaller applied voltage.

I wouldn't like to speculate on exactly how the oscillation is maintained, but I can well see that a meter's autoranging algorithm might work on the assumption that the thing it's measuring has a fairly constant resistance - but in this case, it doesn't. The current in the coil doesn't just depend on the applied voltage, it also depends on how much energy is stored in the coil's magnetic field.

Result: one confused meter, until it's stuck in manual mode which disables the autoranging mechanism. Given a constant applied voltage (or current) for a while, the inductive ringing dies down and the meter is able to report the dc resistance correctly.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 25, 2012, 03:42:20 pm
Just clean probes with IPA next time, no need to return them
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 25, 2012, 03:59:28 pm
One is certainly that the probes aren't conducting as reliably as they should - whether they're dirty, covered in oxide or whatever. I had a very similar experience with a set of probes from Maplin a few weeks ago, and took them straight back as unfit for purpose. Life is too short for test equipment that doesn't do its job properly.

My best guess is that they have a very thin film of PVC left over from the moulding process. A little cleaning with a solvent will strip it right off.

However, serves you right for using Maplin.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: AndyC_772 on August 25, 2012, 04:15:50 pm
Well, yes, agreed - but it also serves Maplin right for selling probes that don't 'just work' out of the box. I think it's good for companies to have products returned from time to time when there's a quality control issue, rather than expecting their customers to do their QC for them.

The Fluke leads I bought to replace them 'just work'.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 25, 2012, 04:20:12 pm
Well, yes, agreed - but it also serves Maplin right for selling probes that don't 'just work' out of the box. I think it's good for companies to have products returned from time to time when there's a quality control issue, rather than expecting their customers to do their QC for them.

The Fluke leads I bought to replace them 'just work'.

Maplin will just throw them in the bin and forget about it.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on August 25, 2012, 10:20:20 pm
So, may use stock probes, or search for something better?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on August 25, 2012, 11:00:26 pm
The ones that come with the multimeter are quite good. Not the cheapo probes that comes with 5-10$ multimeters.  IMHO no need to search for probes before trying the ones that come with this meter.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on August 27, 2012, 12:25:15 am
What was that!?
Result: one confused meter, until it's stuck in manual mode which disables the autoranging mechanism. Given a constant applied voltage (or current) for a while, the inductive ringing dies down and the meter is able to report the dc resistance correctly.

Maybe we could add a Zobel (RC shunt) inside the meter across it 4mm sockets if its inductance that really confuses it? Just a wild guess.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 27, 2012, 03:37:43 am
I'll go check my UT61E with my collection of inductors and transformers and i'll tell ya
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on August 27, 2012, 06:35:25 am
It's just the fact that I will order on the internet, will go a long, why did not immediately order the probes?:)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on August 27, 2012, 09:37:43 am
When you buy anything else, do you buy spare parts for it also because you think what it comes with might be broken?

He's just ONE guy in lots of people that have bought that multimeter and didn't replicate his issue.  My own model has no problems with the probes, they work fine, very fast and accurate continuity tests when touching the probes and all that.

You can probably source probes locally if they're really going to be bad, and even ordering online won't bankrupt you, they're not heavy so shipping would be almost free. It's not something impossible to get after purchase and it won't kill you if you just have to press Manual Range in the special case where you actually might have to test the resistance of a transformer/inductor coil and get this issue. How often do you actually do that?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on August 27, 2012, 11:06:00 am
they're not heavy so shipping would be almost free. ... How often do you actually do that?
It's just because shipping is very long time and takes about 3-4 weeks.
Ok, convinced. ;)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 27, 2012, 11:06:53 am
Nope no issue on mine, tested on common mode inductors and transformers
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 31, 2012, 03:13:02 am
My multi meter software is officially in release. Supports UT61E series and should support other UT60/UT70 models.

v1.0.1 here: http://www.ultradmm.com/Download.aspx (http://www.ultradmm.com/Download.aspx)

Looking for some feedback, suggestions. I'm looking to expand the supported meter list so if you have a meter you'd like to see supported. Please msg me.

Tom

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: korborh on August 31, 2012, 04:00:43 pm
Thanks Tom for your efforts!
I am still waiting on my meter from China, and am eager to try out your software.  :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 31, 2012, 04:08:43 pm
Looking for some feedback, suggestions.

Multiplatform support.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 31, 2012, 04:58:29 pm
It's .Net so technically could be ported to Mono which is multiplatform.

What platform are you interested in?

Looking for some feedback, suggestions.

Multiplatform support.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on August 31, 2012, 05:35:14 pm
Pretty sure he wants linux
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 31, 2012, 05:39:46 pm
Challenge accepted :)

Pretty sure he wants linux
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 31, 2012, 05:47:41 pm
Linux is my primary platform, yes.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 31, 2012, 05:49:29 pm
What distro if you don't mind me asking?


Linux is my primary platform, yes.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 31, 2012, 05:50:29 pm
What distro if you don't mind me asking?


Linux is my primary platform, yes.

Gentoo primarily, but accessing a tty device is the same on every distro. ;)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on August 31, 2012, 05:51:40 pm
I'm more concerned with the UI. I'm using some 3rd party libraries to render the gauges and graphs that might be a challenge to get working under mono.


What distro if you don't mind me asking?


Linux is my primary platform, yes.

Gentoo primarily, but accessing a tty device is the same on every distro. ;)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 31, 2012, 05:53:07 pm
I'm more concerned with the UI. I'm using some 3rd party libraries to render the gauges and graphs that might be a challenge to get working under mono.

UI is distro-independent.

I have precisely no give-a-crap if it's GTK2, GTK3, Qt4, or any of the other libs so long as it doesn't look like it belongs on a mid-90s Mac.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 31, 2012, 06:32:35 pm
I'm looking to expand the supported meter list so if you have a meter you'd like to see supported. Please msg me.

Fortune based meters. Protocol is described in their datasheets, page 31: http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-11_EN.pdf (http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-11_EN.pdf)

Common examples are the rest of the UT61 range, among many many others.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on September 01, 2012, 03:01:26 am
Very easy protocol. Should be a cinch to implement. Though no real means to test it. Do you know what specific meters use this chip?

Tom

I'm looking to expand the supported meter list so if you have a meter you'd like to see supported. Please msg me.

Fortune based meters. Protocol is described in their datasheets, page 31: http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-11_EN.pdf (http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-11_EN.pdf)

Common examples are the rest of the UT61 range, among many many others.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 01, 2012, 03:09:08 am
Very easy protocol. Should be a cinch to implement. Though no real means to test it. Do you know what specific meters use this chip?

Tom

I'm looking to expand the supported meter list so if you have a meter you'd like to see supported. Please msg me.

Fortune based meters. Protocol is described in their datasheets, page 31: http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-11_EN.pdf (http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-11_EN.pdf)

Common examples are the rest of the UT61 range, among many many others.

UT61A through D is an easy example.

The entire UT60 range, as far as I'm aware, uses the FS9721 chip, same protocol.

I have a suitable meter here.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 01, 2012, 03:24:44 am
I would love to see VC8145 included but apparently there's like no info on google that i can find  ???

http://sigrok.org/wiki/Victor_70C (http://sigrok.org/wiki/Victor_70C)
http://sigrok.org/wiki/UNI-T_UT61D (http://sigrok.org/wiki/UNI-T_UT61D)

And Victor 68E uses the same chipset as the UT61E
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 01, 2012, 03:33:07 am
I would love to see VC8145 included but apparently there's like no info on google that i can find  ???

Open one up, tell us what the chip is.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on September 01, 2012, 03:36:19 am
well, if you guys are willing to work with me on testing, I can definitely implement the protocol as per documentation.

Tom

I would love to see VC8145 included but apparently there's like no info on google that i can find  ???

http://sigrok.org/wiki/Victor_70C (http://sigrok.org/wiki/Victor_70C)
http://sigrok.org/wiki/UNI-T_UT61D (http://sigrok.org/wiki/UNI-T_UT61D)

And Victor 68E uses the same chipset as the UT61E
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 01, 2012, 07:09:53 am
well, if you guys are willing to work with me on testing, I can definitely implement the protocol as per documentation.

Tom

I would love to see VC8145 included but apparently there's like no info on google that i can find  ???

http://sigrok.org/wiki/Victor_70C (http://sigrok.org/wiki/Victor_70C)
http://sigrok.org/wiki/UNI-T_UT61D (http://sigrok.org/wiki/UNI-T_UT61D)

And Victor 68E uses the same chipset as the UT61E
Don't worry about that, i don't have it now. I don't need it now either  :P
Why not implement a "in-program update" ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mianchen on September 01, 2012, 05:16:21 pm
After reading this thread from page 1 to 18, I  ended up on the DD site and ordered myself a 61E from DD for £33 :) Even Taobao sells UT61E for over 300 RMB (~£30, $50).

BTW "10offsale" code (found by googling) saves you 10% when check out, better than nothing at all :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 01, 2012, 05:32:01 pm
After reading this thread from page 1 to 18, I  ended up on the DD site and ordered myself a 61E from DD for £33 :) Even Taobao sells UT61E for over 300 RMB (~£30, $50).

BTW "10offsale" code (found by googling) saves you 10% when check out, better than nothing at all :)

220 RMB lowest i saw ...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: BThunderW on September 01, 2012, 07:53:54 pm
Since UltraDMM is quickly expanding outside of the UT61E line,  I've created a new UltraDMM thread here: https://www.eevblog.com/forum/projects-designs-and-technical-stuff/ultradmm-software-project/ (https://www.eevblog.com/forum/projects-designs-and-technical-stuff/ultradmm-software-project/)


Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on September 03, 2012, 11:00:56 am
Some queries

1>If I purchase the UT61E from DD & use the 10% off coupon  then should I be eligible for the free shipping(registered post with tracking number) cuz it will be about  $ 49.491 & hence its be less than 50$.

2>In DD there are two skus for UT61E
ie; 1>SKU: A024000BTO--$56.99
     2>SKU: A2484000FN--$54.99
as discussed earlier the price difference is due to different suppliers,the first sku is marked as new,so is it the 1st sku is from the next version with Back-light led or with a auto-power off feature,or from new stock or a complete marketing gimmick ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 03, 2012, 04:43:59 pm
Some queries

1>If I purchase the UT61E from DD & use the 10% off coupon  then should I be eligible for the free shipping(registered post with tracking number) cuz it will be about  $ 49.491 & hence its be less than 50$.

2>In DD there are two skus for UT61E
ie; 1>SKU: A024000BTO--$56.99
     2>SKU: A2484000FN--$54.99
as discussed earlier the price difference is due to different suppliers,the first sku is marked as new,so is it the 1st sku is from the next version with Back-light led or with a auto-power off feature,or from new stock or a complete marketing gimmick ?

Huh? It's already established it's a error
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on September 04, 2012, 07:29:21 am
And Victor 68E uses the same chipset as the UT61E
I can't find any 68E on official site, can you get me URL? :)

Huh? It's already established it's a error
If I'm right to undarstanding - no, that prices still there about 2-3 weeks. The manager's can give referal url with 10% off discount, and thats more then $50. I'm not seen any price on 61E below $50 with free shipping. :( :( :(
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 04, 2012, 07:34:50 am
Use a taobao agent
http://tbcart.com/Product/8525801294/Genuine+LiDE+%3Cspan+class%3DH%3EUT+%3C+span%3E+%3Cspan+class%3DH%3E61+%3C+span%3E+%3Cspan+class%3DH%3EE+%3C+span%3E+can+be+connected+to+PC+with+data+cable+digital+multimeter+%28limited+sales%29/ (http://tbcart.com/Product/8525801294/Genuine+LiDE+%3Cspan+class%3DH%3EUT+%3C+span%3E+%3Cspan+class%3DH%3E61+%3C+span%3E+%3Cspan+class%3DH%3EE+%3C+span%3E+can+be+connected+to+PC+with+data+cable+digital+multimeter+%28limited+sales%29/)

VC86E*
http://www.china-victor.com/cn/product_data.aspx?ClassID=168&ID=128 (http://www.china-victor.com/cn/product_data.aspx?ClassID=168&ID=128)
http://tbcart.com/Product/12890686878/Genuine+victory+digital+multimeter+%3Cspan+class%3DH%3EVC+%3C+span%3E+%3Cspan+class%3DH%3E86+%3C+span%3E+%3Cspan+class%3DH%3EE+%3C+span%3E+four+and+a+half+high-accuracy+frequency-temperature+USB+computer+interface/ (http://tbcart.com/Product/12890686878/Genuine+victory+digital+multimeter+%3Cspan+class%3DH%3EVC+%3C+span%3E+%3Cspan+class%3DH%3E86+%3C+span%3E+%3Cspan+class%3DH%3EE+%3C+span%3E+four+and+a+half+high-accuracy+frequency-temperature+USB+computer+interface/)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on September 04, 2012, 12:32:02 pm
And Victor 68E uses the same chipset as the UT61E
I can't find any 68E on official site, can you get me URL? :)

Huh? It's already established it's a error
If I'm right to undarstanding - no, that prices still there about 2-3 weeks. The manager's can give referal url with 10% off discount, and thats more then $50. I'm not seen any price on 61E below $50 with free shipping. :( :( :(

I think this is the official site of Victor 86E
http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.china-victor.com%2Fcn%2Fproduct_data.aspx%3FClassID%3D168%26ID%3D128&act=url (http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.china-victor.com%2Fcn%2Fproduct_data.aspx%3FClassID%3D168%26ID%3D128&act=url)

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on September 04, 2012, 12:39:16 pm
On comparison I found that VICTOR 86E wins in every department(by spec sheet) with Uni-t 61e,it has all the features that Uni-t has+some extra like Back Light(can see it in picture but they didn't  mentioned),autooff,rs232 usb,temp,new pc software & has a overall better accuracy,

But only thing I can't find is True RMS,with the given AC accuracy by spec sheet it perhaps has TRMS but not mentioned,whether it has same chip is also unknown.

I Don't know of this brand though,
So is this Dmm is better & more reliable that 61E,plz provide views suggestions & if something I overlooked.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 04, 2012, 04:28:01 pm
Probably worse, given that it's from Victor and nobody got their hands on one
(Somebody nearly did but that extinct from EEVBlog Forums Greek guy kirikakos told him to "avoid" like dog's poo)

But yeah ... UNi-T is modest with their ratings, 0.1% is the least you can get from it and sometimes when UNi-T does things properly they miss out some features  :P
I will get a 86E for review in 1-2 months time, until then you can cross your fingers but i guess it should be TRMS because it is around the same price bracket

and it's the same chipset but who says the UNI-T doesn't have RS232 ... of course it has but it isn't "direct USB" ffs it's not an extra but a bonus because you don't need to bother with a frikkin' RS232 converter

Buying from a taobao agent is a big plus because i am getting massive price differences here ... due to no such thing as "free shipping"
Over at dinodirect ( which is the cheapest outside of taobao agents ) the UT61E costs 66SGD with the 10% discount
at taobao it costs 50$SGD w/ shipping

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 05, 2012, 07:12:19 pm
For all those who have whined about the fuses:

(https://lh6.googleusercontent.com/-TQGqnaJCDno/UEejpKMuXXI/AAAAAAAABCI/H_tcK0HRWEY/s800/IMG_20120905_174358.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 05, 2012, 07:46:42 pm
Ok, found sockets. I don't think i'm gonna upgrade the 1A fuse
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 05, 2012, 07:52:01 pm
Where did you find the sockets ? and the 1A fuse ...

It's a 500mA fuse. The range is only 220mA, no need for 1A. Both sockets and fuses are salvage from a dead meter, should be available from the likes of Digikey. The fuses certainly are. I had to file the pins down a bit for a couple of them, though, I think the mA range fuse is meant to be a 6.3x32 (like the Fluke 17B, actually), not 10x38.

I'll have to replace the 20A with a 10A one some time, although I may just see how hot things get with 20A going through it, it's a 22A range.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on September 05, 2012, 09:11:05 pm
For all those who have whined about the fuses:

(https://lh6.googleusercontent.com/-TQGqnaJCDno/UEejpKMuXXI/AAAAAAAABCI/H_tcK0HRWEY/s800/IMG_20120905_174358.jpg)


My memory could be wrong (it often is, just ask my wife ;D) but I don't remember too many people complaining about the fuses on this device. I remember a LOT of complaints about the glass fuses in the 71 series. Also, since I am a bit of a n00b are you commenting that things got worse or are those better? I really don't know a damn thing about fuses heh.

As for the Victor, I don't know what to think about it. I do know that Victor, unlike Uni-T, is not bashful about overstating their capabilities. That alone is enough to make me trust Uni-T much more. Having compared the listed specs in the respective manuals seems that Victor specifies a tighter percent accuracy but the adds on a higher count number to the accuracy. Uni-T seems to allow wider % ranges but lower counts. Also, Uni-T seems to be very consistent with the number of counts. Most being in the single digits and not changing much across ranges. Victor though seems to allow double digit counts in the error and tends to change them a lot more from range to range. Additionally, when it comes to AC measurements, Uni-T tests 45Hz-1kHz and provides values and 1kHz to 10kHz, while Victor only specs the range from 40-400Hz. It almost looks to me that Victor is playing a bit fast and loose with the truth on many of these measurements. Especially when you consider the fact that they list their voltage accuracy at 0.05% and Cyrustek lists the non-linearity of the ES51922 measurement at 0.03%. This means that Victor is allowing only 0.02% error in the rest of the device for those measurements. Is it doable? Yeah, but would I trust a company like victor to do it?

Also, I was searching recently and check out this blue OEM version of the UT61E. I think it looks kinda slick, though I def like the red better.
(http://www.industrial-needs.com/technical-gallery/measurement-overview/technical-pictures/normal_trms_multimeter_pce-ut61e-12~0.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 05, 2012, 09:13:14 pm
Ok, found sockets. I don't think i'm gonna upgrade the 1A fuse

Not much point in spending money on it unless you're working with >50VDC. They're good up to 250VAC of course, and nothing higher voltage AC is going to be drawing puny currents like that (generally).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 05, 2012, 09:17:50 pm
My memory could be wrong (it often is, just ask my wife ;D) but I don't remember too many people complaining about the fuses on this device. I remember a LOT of complaints about the glass fuses in the 71 series. Also, since I am a bit of a n00b are you commenting that things got worse or are those better? I really don't know a damn thing about fuses heh.

Oh, there's been whining about the usage of BS1362 fuses, and plenty of it..

These fuses are an upgrade. In price, too, they're about £5 each to change, vs about 30p for the originals. But I happen to have a couple of spares.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on September 05, 2012, 09:36:48 pm
On comparison I found that VICTOR 86E wins in every department(by spec sheet) with Uni-t 61e
Very similar to this http://www.proskit.com/test-instruments/multimeters/dual-display-digital-multimeter-w-usb-connector (http://www.proskit.com/test-instruments/multimeters/dual-display-digital-multimeter-w-usb-connector)
But if no TRMS - it'not worth it, I think. :-\
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 06, 2012, 08:18:50 am

Also, I was searching recently and check out this blue OEM version of the UT61E. I think it looks kinda slick, though I def like the red better.
(http://www.industrial-needs.com/technical-gallery/measurement-overview/technical-pictures/normal_trms_multimeter_pce-ut61e-12~0.jpg)

There's no "OEM" version, just restamped custom versions
There are even green versions of the 61E
On comparison I found that VICTOR 86E wins in every department(by spec sheet) with Uni-t 61e
Very similar to this http://www.proskit.com/test-instruments/multimeters/dual-display-digital-multimeter-w-usb-connector (http://www.proskit.com/test-instruments/multimeters/dual-display-digital-multimeter-w-usb-connector)
But if no TRMS - it'not worth it, I think. :-\

OK : Declaration
Stay away from the VC86E, even the local chinese don't like the quality at all

I just saw the V&A VA30S but that's no where to be found
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on September 06, 2012, 06:45:39 pm

Also, I was searching recently and check out this blue OEM version of the UT61E. I think it looks kinda slick, though I def like the red better.
(http://www.industrial-needs.com/technical-gallery/measurement-overview/technical-pictures/normal_trms_multimeter_pce-ut61e-12~0.jpg)

There's no "OEM" version, just restamped custom versions
There are even green versions of the 61E
On comparison I found that VICTOR 86E wins in every department(by spec sheet) with Uni-t 61e
Very similar to this http://www.proskit.com/test-instruments/multimeters/dual-display-digital-multimeter-w-usb-connector (http://www.proskit.com/test-instruments/multimeters/dual-display-digital-multimeter-w-usb-connector)
But if no TRMS - it'not worth it, I think. :-\

OK : Declaration
Stay away from the VC86E, even the local chinese don't like the quality at all

I just saw the V&A VA30S but that's no where to be found

That's basically what I meant when I said OEM. Just rebadged.


As for the VA30S the stats in general seem to be a wash with the UT61E. ACV stats seem to be better overall, with ACA being more or less equivalent. DCV Stats seem to be uniformly worse, DCA stats are better. Resistance is definitely worse than the UT61E. Capacitance is markedly better (albeit at much higher count error). Frequency error is much worse (0.05%+8) versus 0.01%+4 for the Uni-T.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 06, 2012, 06:49:23 pm
Still avoiding that one . i know the MS8240D exists but it seems nobody sells it  :'(
Plus it uses every single function of the ES51922! Too bad then  :'( :'( :'(

Oh yeah monkeh, i was thinking of installing MOVs where the sparkgap footprint is, should i go for 1.5kVDC max MOVs or 890VDC max MOVs? (Obviously their clamping voltage is different)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 06, 2012, 07:00:49 pm
Oh yeah monkeh, i was thinking of installing MOVs where the sparkgap footprint is, should i go for 1.5kVDC max MOVs or 890VDC max MOVs? (Obviously their clamping voltage is different)

Ask someone familiar with input protection. ;)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 06, 2012, 07:10:13 pm
I don't know anyone who does  :(
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on September 06, 2012, 09:29:46 pm
What is the max voltage that you will use the meter for? I would go for the 890V units, that will cover most mains applications aside from ferroresonant units, where you will pop the meter anyway on the 1.5kV typical of the separate tank coils.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ProBang on September 07, 2012, 04:01:08 am
[...] i know the MS8240D exists but it seems nobody sells it  :'( [...]

Perhaps, Uni-T bought the complete production of the ES51922? Made a exclusive contract?

BTW: I've now ordered a UT-61E, too. From DinoDirect.
At this time, right from the beginning on, it looks like, that was a big failure...
I'd used a payment- system which is offered from DD for Customers in Germany (and some other countries).
But they can't handle it.
It seems, this transaction will be a thriller...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 07, 2012, 04:36:04 am
Not so exclusive if Victor is also using it  :o
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on September 08, 2012, 11:19:42 am

Also, I was searching recently and check out this blue OEM version of the UT61E. I think it looks kinda slick, though I def like the red better.
(http://www.industrial-needs.com/technical-gallery/measurement-overview/technical-pictures/normal_trms_multimeter_pce-ut61e-12~0.jpg)

Blue will surely fare better on dirt, scratches, and stains in the long run. If taking into account what is possible across brands, worse offender is bright yellow in this respect. Next is orange. Red is so so, dark green is good.  Black and dark grey are good also but not so commonly offered.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: samgab on September 08, 2012, 12:24:50 pm
I just ordered one of these, so when it arrives in a few weeks, the first thing I'll be doing will be - not turning it on - taking it apart, to see if the new iterations still have the same bodge jobs from 2011, or if the pcb has been changed in any way since then. I don't know how recent a batch the one I ordered will be drawn from though.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 08, 2012, 03:24:04 pm
See my teardowns, a little bit of botch but if it doesn't affect performance or usability i don't care.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ProBang on September 10, 2012, 12:04:08 pm
Hello.


FYI: Mastech MS8240D

It seems, the 8240D is available. Not from Mastech...
Re-badged as Peaktech 3430 USB:

http://www.peaktech.de/productdetail/kategorie/digital---handmultimeter/produkt/peaktech-3430-usb.html (http://www.peaktech.de/productdetail/kategorie/digital---handmultimeter/produkt/peaktech-3430-usb.html)

And it is in stock. For example:

http://www.reichelt.de/Multimeter-digital/PEAKTECH-3430U/3//index.html?ACTION=3;GROUPID=4058;ARTICLE=110389;SHOW=1;START=0;OFFSET=16;SID=12UD8EzX8AAAIAAGPGZOA75f1179d84f5a256d2f165678f2ca529;CCOUNTRY=628; (http://www.reichelt.de/Multimeter-digital/PEAKTECH-3430U/3//index.html?ACTION=3;GROUPID=4058;ARTICLE=110389;SHOW=1;START=0;OFFSET=16;SID=12UD8EzX8AAAIAAGPGZOA75f1179d84f5a256d2f165678f2ca529;CCOUNTRY=628;)

To comparing the price, the UT-61E from the same seller:

http://www.reichelt.de/Multimeter-digital/UT-61E/3/index.html?;ACTION=3;LA=446;ARTICLE=97151;GROUPID=4058;artnr=UT+61E;SID=12UD8EzX8AAAIAAGPGZOA75f1179d84f5a256d2f165678f2ca529 (http://www.reichelt.de/Multimeter-digital/UT-61E/3/index.html?;ACTION=3;LA=446;ARTICLE=97151;GROUPID=4058;artnr=UT+61E;SID=12UD8EzX8AAAIAAGPGZOA75f1179d84f5a256d2f165678f2ca529)

BTW: The payment for my order is meanwhile confirmed. (What a surprise...)
Now the order is stated as "approved". Waiting for "stocking up".
I'm curios, how long it will last...
It's just a test. That was the first order I've placed immediately by a seller in China.

Greetings,


Hartmut
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 10, 2012, 01:01:35 pm
22,000 counts and it's showing 343.00 hmm...
In any case, that site you showed me already far too expensive for both models (it being titled with "Reich" is interesting  ;D ;D ;D)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Tepe on September 10, 2012, 02:04:28 pm
22,000 counts and it's showing 343.00 hmm...
In any case, that site you showed me already far too expensive for both models (it being titled with "Reich" is interesting  ;D ;D ;D)
The UNI-Ts sold by Reichelt are fitted with beefy fuses and German text on the back.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 10, 2012, 02:27:04 pm
Is it? Let's have some pictures!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Tepe on September 10, 2012, 04:41:48 pm
Is it? Let's have some pictures!

(https://www.eevblog.com/forum/product-reviews-photos-and-discussion/uni-t-ut61e-multimeter-teardown-photos/?action=dlattach;attach=29867;image)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on September 10, 2012, 05:34:43 pm
Is it? Let's have some pictures!

(https://www.eevblog.com/forum/product-reviews-photos-and-discussion/uni-t-ut61e-multimeter-teardown-photos/?action=dlattach;attach=29867;image)

Whoa more than just the fuse has changed. The resistor bridge is gone up top. Much beefier input protection it looks like (i'm guessing the black barrel is some sort of MOV or something). The circuit board itself is dramatically different. MELF resistors at the bottom. It looks like most things have been moved, traces rerun, etc. What was the manufacture date on the card inside the manual?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 10, 2012, 05:58:57 pm
Whoa more than just the fuse has changed. The resistor bridge is gone up top.

That would be because it's a UT61C, not a UT61E.

As I thought, that's a 5x32 or 6.3x32 rather than a 10x38, for the mA range. Quite acceptable.

22,000 counts and it's showing 343.00 hmm...

Note the model number. Now note the reading. Funny, that. The chip allows for external control of the LCD.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 10, 2012, 06:13:27 pm
So did you manage to fit a 10x38 overly-tight or what? Actually i'm looking to put just a 6x32mm because after all, blowing up mA fuses is far more common than blowing up A fuses thus much cheaper and i don't think you would be using mA too much on 50kA systems are you  ;)

Well that black thing can be two things: MOVs or Sparkgaps
And the fuses appear to be pretty cheap, find them all over in taobao. Is it? I'm not sure
But i'm sure the mods won't cost you that much extra, for the extra safety i'm modifiying BOTH of mine

6x32 or 10x38 i'm not sure ...
But i notice the glaring omission of a input resistor R39 on the UT61E, which is on the PCB but it isn't there! I guess you can't include a input protection resistor when you're measuring 220MHz

Here's a reason to stay away from the VC86E, it's just crap.
(http://pic.hifidiy.net/forumid_2/11062018151cfd67c871bd4f8d.jpg)

At least the mov's included and i bet the buzzer doesn't sound half as good as the UT61E does, plus it lacks relative which is a total deal killer
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Tepe on September 10, 2012, 07:46:07 pm
That would be because it's a UT61C, not a UT61E.

As I thought, that's a 5x32 or 6.3x32 rather than a 10x38, for the mA range. Quite acceptable.
Yes, it's a UT61C.

The Reichelt supplied manual (in German, they even claim copyright) calls for  a ceramic 6x32, 0.5 A 600 V fast blow fuse for the mA range.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Tepe on September 10, 2012, 07:51:06 pm
(it being titled with "Reich" is interesting  ;D ;D ;D)
Only in the way "coworker" contains "cow"  ;)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 10, 2012, 08:12:26 pm
So did you manage to fit a 10x38 overly-tight or what? Actually i'm looking to put just a 6x32mm because after all, blowing up mA fuses is far more common than blowing up A fuses thus much cheaper and i don't think you would be using mA too much on 50kA systems are you  ;)

Had to modify the clips.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Oracle on September 11, 2012, 11:33:39 am
well, it's actually a better DMM than i got:

http://www.aecsz.com/show4.htm (http://www.aecsz.com/show4.htm)

useful if i have to make relays schematics: so if i do something wrong at least i don't have destroyed a $500 DMM.... i used as my first multimeter for electronic also, but lasted a couple of weeks...

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 16, 2012, 10:34:35 am
So i got down to do some tests on power consumption (naturally with a almost identical twin)
9V (Batteries start fresh at 10V but that's unloaded)
1.5mA on capacitance even while measuring a 10mF cap... Big i know
1-2mA on voltage Actually i was pretty shocked it only draws that much at this price point and best part is that the screen is actually more viewable than the 87v As in better contrast and brightness(This is a true reply, my friend uses the 87V at his college, well i mean everyone there uses it)
Didn't really test the rest but when it's in continuity mode with beeper sounding it's about 4-5mA

Okay, here's the most important part some might want to know.
Low voltage performance? Measured at PSU but it doesn't matter, my psu is pretty accurate but i still used it's twin i got from DD to measure the PSU voltage
Battery LV warning? Starts at 5.35V and stops at 5.45V
Voltage where the measurement starts to drift? Doesn't seem to drift above 3.5V but i can't really tell. Even my ET-845 seems to drift way more with fresh batteries, the UT61E doesn't seem to drift before it turns off! I was a little worried when i saw it happening yesterday then i forgot i wasn't using banana plugs
Voltage where it turns on? 2.1 Seems to be right, the datasheet says -2.5 to -3.5 so i'm seeing witchcraft here or is it a buck-boost converter?
I'm seeing ±5V on the AD737J so i'm pretty sure the UT-61E has a buck-boost converter

So my testing is complete, if you do need anymore measurements i'm glad to provide
(This lodestar 8202/8203 psu is freaking impressive, 33 year old caps and they hardly drift or have hardly any noise at all!)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on September 16, 2012, 03:57:06 pm
1.5mA on capacitance even while measuring a 10mF cap... Big i know
1-2mA on voltage Actually i was pretty shocked it only draws that much at this price point
What would a multimeter like this usually draw at this price point? I'd this related the resistance of the input?

 
Voltage where the measurement starts to drift? Doesn't seem to drift above 3.5V but i can't really tell. Even my ET-845 seems to drift way more with fresh batteries, It doesn't seem to drift before it turns off! I was a little worried when i saw it happening yesterday then i forgot i wasn't using banana plugs
This part is a bit confusing to me. So are you saying the UT-61E drifts below 3.5V or it doesn't drift before it turns off (or is that in reference to the ET-845). I'm confused about the not using banana plugs comment. Is that in reference to the UT-61E or the ET-845?


Either way the more I see of this meter being put through its paces the higher quality it seems to become. Really it's only major flaw is the input protection, it's not horrible but it's not premium level.  Some will complain about no backlight, personally I have never needed it. All this for under $50 to me is outstanding.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 16, 2012, 04:25:47 pm
Oh, i apologize for confusing you.
What i meant was i did the test again and realized it doesn't drift before turning off! Because the twin was measuring Supply voltage so i used my ET-845 to measure input voltage which drifted even more than the UT61E so i'm pretty darn sure there's almost zero drift.

Need more tests? I shall grab use my stopwatch and time it measuring 10mF and comparing it to (well, a proper MS5308 LCR meter i have in my mind won't measure to 10mF so ah well)

And also 10MOhms accuracy ( Have tens of those lying around ) comparing it with the LCR meter
And also mV accuracy ... this will be a tough one but whatever. Frequency's spot on
Next, making use of the AC RMS and see it's accuracy.

What other meter at this price range that you can easily find that is quite well built (you just have to love the stiff case!) that is based on the ES51922? You can't.
MS8240D < not easy to find, VC86E < Crap quality even at the same price range and it lacks relative oddly, Yihua V&A VA30S < Brand New product so hard to find

And to top it off, show me a 50$ meter that has lighting fast continuity and autoranging (Well, if it's not lighting fast for ya, clean your probes with some IPA)
I find "lightning-fast" response to be very useful if you don't want to waste time and quickly *BEEP..BEEP..BEEP..BEEP*
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on September 16, 2012, 05:59:10 pm
No need to apologize, you said what I was thinking you were but just wasn't quite sure. :D That's really awesome that there is more or less no drift based on voltage.  I am wondering if the little transistor sot23 like ic labeled w1 (what the heck does the w part identifier mean) is done sort of charge pump based buck boost or is it just a 3.voltage regulator. Otherwise I can't find a single ic that would control buck boost features.

I was really really impressed with its accuracy on the 2.2mF caps I tried. They were HUGE 100V  2200uF caps and it read them as within 1.0x% of their listed value. I was both impressed with the precision of the caps (they didn't vary until fourth digit) and the meter (reading these enormous caps at within 1%). I didn't even think about timing it.

I agree the IC by cyrustek is awesome. That being said the vc86e shows that with our proper design you still get crap. It shows that Uni-T took the time to do it right. I agree that case is awesome. Rigid, feels good in the hands, the stand is solid and functional (no bending). The display had more or less 180o viewing angles and easy to read. Yeah and it's fast. I'd love to see Dave throw this one in his next $50 meter shootout and watch it just annihilate the competition.

Also aren't the MS8240d and va30s more expensive? Like around $80 and $150 respectively? Not that those prices are bad, it just illustrates how good of a deal this meter is.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 16, 2012, 11:57:58 pm
Well yeah, i don't know about the prices of the MS8240D. Googling it till the 5th page didn't help
Neither the VA30S
On paper though, the VA30S has everything but Yihua V&A is not a company you look for quality.
But if both of them end up that expensive i might as well buy another MS8218. Mastech is even more well-known for quality
Fact is, the UNI-T UT61E is very highly revered in china and they too hate the UT71 ... I guess it will take the other companies years to make another kickass product that even matches the UT61E.
Anyway, i was looking up the prices on taobao and it's incredibly cheap  :o Actually it only costs 40SGD and that translates to nearly 32USD ... i should have used taobao agents in the first place
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on September 17, 2012, 12:34:01 am
i was looking up the prices on taobao and it's incredibly cheap  :o Actually it only costs 40SGD and that translates to nearly 32USD ... i should have used taobao agents in the first place

Do you have the link for the $32 61E on Taobao?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 17, 2012, 08:52:03 am
Do you have the link for the $32 61E on Taobao?
http://item.taobao.com/item.htm?id=15573161789&ali_trackid=2:mm_14507416_2297358_8935934:1347871879_4k9_375016240# (http://item.taobao.com/item.htm?id=15573161789&ali_trackid=2:mm_14507416_2297358_8935934:1347871879_4k9_375016240#)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on September 18, 2012, 10:50:39 am
Do you have the link for the $32 61E on Taobao?
http://item.taobao.com/item.htm?id=15573161789&ali_trackid=2:mm_14507416_2297358_8935934:1347871879_4k9_375016240# (http://item.taobao.com/item.htm?id=15573161789&ali_trackid=2:mm_14507416_2297358_8935934:1347871879_4k9_375016240#)

English Tabao but don't know their genuiness-http://www.englishtaobao.com/taobao?SearchText=uni-t+61E&catId=0

1>Visited Tabao but can't find the shipping calculation for registered post,using google translation.

2>So browsed & found English Tabao but the prices are way higher & are as on par as DD or Dx,

3>In English version there are many 61Es,is those are diffrent supplier ?

4>Can't understand why the chineese ver & English version has such a variation in price.

5>Last thing is,is Tabao is dependeble (supplies genuine part or not)as DD or DX,?Can anyone who had purchase from Tabao can tell the after sales service of them.

Plz en light.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on September 18, 2012, 11:05:38 am
I am a frequent Taobao buyer and in my experience if you're buying Chinese brand products it's basically always genuine. If it's imported stuff the price will reflect it and you'll get better deals elsewhere.

The price difference between Chinese and English versions mostly has to do with the affordability and price expectations of the different markets. Simply and bluntly put , English buyers are getting ripped.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on September 18, 2012, 11:14:15 am
And BTW, I don't think the Chinese Taobao is intended to be used by overseas buyers. The sellers generally will not ship beyond Hong Kong and Taiwan. Plus a lot of them expect you to contact them to confirm shipping fee before payment, in Chinese!

Aliexpress.com is the official overseas facing version of Taobao. But again, you'll see vastly different pricing unfortunately.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 18, 2012, 11:16:47 am
If you are overseas don't use taobao or "englishtaobao" Use a taobao agent, much cheaper.

For me it works out so well and my agent is very trustable, only 7$ for the first 500g! and 4$ for the following 500g w/ EMS
And they pack so damn well, unlike DX!

And BTW, I don't think the Chinese Taobao is intended to be used by overseas buyers. The sellers generally will not ship beyond Hong Kong and Taiwan. Plus a lot of them expect you to contact them to confirm shipping fee before payment, in Chinese!

Aliexpress.com is the official overseas facing version of Taobao. But again, you'll see vastly different pricing unfortunately.
Prices are mostly quoted in "ship anywhere" prices
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: darrylp on September 18, 2012, 11:43:23 am
So the ut61e has peak mode. Giving what difference to the min / max mode seen on other multi meters ?

I see the actual chip used supports both modes. So what is the diff ?



Sent from my HTC Desire
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on September 18, 2012, 12:11:39 pm
So the ut61e has peak mode. Giving what difference to the min / max mode seen on other multi meters ?

I see the actual chip used supports both modes. So what is the diff ?



Sent from my HTC Desire

From the Fluke website:

http://www.fluke.com/fluke/m3en/support/digital-multimeter-faq.htm (http://www.fluke.com/fluke/m3en/support/digital-multimeter-faq.htm)

Q: What is the difference in the Min/Max and Peak modes on multimeters?
A: The Min/Max mode is as its name implies, it is the highest and lowest reading that the multimeter measured from the time the Min/Max record mode was started. Typically, they need the measured signal's maximum or minimum to be 200 to 350 milliseconds long or longer to get an accurate reading. They work from any mode such as volts dc, true-rms volts ac, resistance, and current functions. Peak mode measures the positive and negative peak voltage of a signal. For the 120 volt ac line, the peaks will read +169 volts and -169 volts (120 V x 1.414 = 169 V for a clean sine wave). Typically they will work for peaks that are 250 microseconds or longer.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: darrylp on September 18, 2012, 12:21:54 pm
So the min/max sounds more useful than peak mode to me from that fluke text.

Thanks, Darryl

Sent from my HTC Desire
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 18, 2012, 12:59:11 pm
No actually you're not right nor not wrong.

It's good for capturing what min/max can't capture, it shows you the peak voltages in DC
But if it's in AC it shows you the peak voltage (non-rms)
Or very fast changing voltages
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: darrylp on September 18, 2012, 06:49:21 pm
from reading the ES51922 datsheet the peak mode needs a 100us pulse to be able to read / capture.

the min/max works on many more functions than just voltage / current that the peak works on.

hmm, think i might get one of these meters and make a few mod's.  ie this peak / min/max a backlight and the auto power off, all look very doa-ble from the UT61e schematic and the data sheet.

thanks all

:-)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on September 19, 2012, 09:55:03 pm
It is true that when 61E continuity test leads to change the polarity?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 19, 2012, 11:55:34 pm
It is true that when 61E continuity test leads to change the polarity?

You want to try that one again?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ModemHead on September 20, 2012, 12:26:12 am
It is true that when 61E continuity test leads to change the polarity?

You want to try that one again?
The red lead is negative and the black lead is positive in both Ohms and Continuity mode on the UT61E.  The diode check mode is normal, however.  I think that's what he's referring to.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 20, 2012, 04:43:24 am
It's a fact - it's written in the manual. -1.2V OC Voltage
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: korborh on September 20, 2012, 05:25:56 am
Just received mine from Dinodirect in perfect shape.
Compared it to my 87V and I like the accuracy. The low capacitance measurement is great.
The probes tips needed some filing to remove the crappy coating that was preventing proper continuity detection.
Opened it up and all looked good, except that one of the fuses was half way out of the retaining clip. I pushed it back in.

Overall I am extremely pleased with this meter .  ;D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: glicos on September 22, 2012, 11:24:05 pm
The amazing thing is that it actually has a LPF ...

Not that it's enabled on the UT61E.

It is ... It's enabled!

Like to verify  T4P, is LPF refers to low pass filter like in fluke 87V usefull for variable frequency drive measurements??
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 23, 2012, 12:06:35 am
The amazing thing is that it actually has a LPF ...

Not that it's enabled on the UT61E.

It is ... It's enabled!

Like to verify  T4P, is LPF refers to low pass filter like in fluke 87V usefull for variable frequency drive measurements??

Yes, but it is not enabled on the UT61E.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on September 23, 2012, 06:37:00 am
Just received mine from Dinodirect in perfect shape.
Compared it to my 87V and I like the accuracy. The low capacitance measurement is great.
The probes tips needed some filing to remove the crappy coating that was preventing proper continuity detection.
Opened it up and all looked good, except that one of the fuses was half way out of the retaining clip. I pushed it back in.

Overall I am extremely pleased with this meter .  ;D

I tend to reach for it first a lot too, since it does a round of things well and fast. Mine's original UNI-T branded battery lasted little though until the warning started flashing here and there. It was at 6.5V already. I hope it was not that good a battery and it isn't the data com being always on by default.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 23, 2012, 07:13:59 am
Just received mine from Dinodirect in perfect shape.
Compared it to my 87V and I like the accuracy. The low capacitance measurement is great.
The probes tips needed some filing to remove the crappy coating that was preventing proper continuity detection.
Opened it up and all looked good, except that one of the fuses was half way out of the retaining clip. I pushed it back in.

Overall I am extremely pleased with this meter .  ;D

I tend to reach for it first a lot too, since it does a round of things well and fast. Mine's original UNI-T branded battery lasted little though until the warning started flashing here and there. It was at 6.5V already. I hope it was not that good a battery and it isn't the data com being always on by default.
how long did you use it for? (Ah yes, i don't trust the batteries anyway) The Data's 24/7 on as long as you don't do a mod
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on September 23, 2012, 06:32:24 pm
3 months average to light use not daily.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on September 23, 2012, 06:36:02 pm
Say a couple of tens of hours the most. Data being factory set permanently on is crap amateurism design by the way in that department if you agree.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on September 23, 2012, 06:48:57 pm
Data transmission doesn't put much strain on the battery. Only uses 0.2 mA on the Uni-T 71D. Probably the same on the 61E.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 23, 2012, 06:50:08 pm
Say a couple of tens of hours the most. Data being factory set permanently on is crap amateurism design by the way in that department if you agree.
Do you really have a choice? Read the chip's datasheet. Unless it was a new design to have a dual function switch to switch of RS232 which turns on APO
There isn't a extra button because they got laaaaazy! The hold button isn't used for a backlight because holding it down for 3secs enters delayed hold
Say a couple of tens of hours the most. Data being factory set permanently on is crap amateurism design by the way in that department if you agree.
1-2mA draw with data on, let's just say the stock battery is shit. Use a GP green battery then, those things go for 24hours with 8mA draw so you'll get about 100-200hours lifetime!  ;D NOTE: Continuity draws 5-6mA
Data transmission doesn't put much strain on the battery. Only uses 0.2 mA on the Uni-T 71D. Probably the same on the 61E.
Don't know about that but that is worth a try. 0.2mA is alot when you are talking about PP3 batteries
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on September 23, 2012, 07:57:50 pm
It's a design choice, nobody advertised this meter as having long time logging. 

I'd rather just get a LT1610 (http://cds.linear.com/docs/Datasheet/1610f.pdf) and boost 2 AA (probably a bit of hard fit though) or 2 x AAA rechargable batteries up to 7-8v (high enough to not get low battery indicator)... even at 75-80% efficiency at 3-5 mA the meter uses, the AAA batteries will last more than a 9v battery.

Even non rechargeable AAA batteries would last longer than 9v batteries.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on September 23, 2012, 08:17:50 pm
They just wanted same casing and buttons across the 61 gamut of models is my guess, simply volume economy. The crap stuff possibly goes to the management to be fair. Who designer would not take advantage of the back-light or would even bare to stare at the screen symbol with the S in it when the DMM is not doing data logging at the time, no matter if not taxing even. I spare the registered trademark phrase ''you can fly to the moon on 200uA'' to Dave of course. ;)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 23, 2012, 09:25:00 pm
They wanted to keep the look similar and not having to do a total redesign again. After all, they have one too many product ranges already and the UT-60 series was always more well built than the UT-70 so the UT61 and UT71 are the modern (2008) replacements
and... the UT60H (the top of the line) never had any backlight ...
I'd rather just get a LT1610 (http://cds.linear.com/docs/Datasheet/1610f.pdf) and boost 2 AA (probably a bit of hard fit though) or 2 x AAA rechargable batteries up to 7-8v (high enough to not get low battery indicator)... even at 75-80% efficiency at 3-5 mA the meter uses, the AAA batteries will last more than a 9v battery.
7-8V is way beyond low batt indicator, a 18650 almost goes in which means it doesn't fit. A Double-A sits on the battery terminals How about a 10400/14500?(AAA/AA respectively) size
With http://dx.com/p/ultra-fire-14500-3-6v-900mah-2pack-975?item=3. (http://dx.com/p/ultra-fire-14500-3-6v-900mah-2pack-975?item=3.) (Accurate to about 750mAH, not bad.)

OKAY! the off-the-shelf AA holder doesn't fit. Well time for 10440
http://dx.com/p/fandyfire-10440-3-7v-600mah-batteries-blue-pair-91701?item=3 (http://dx.com/p/fandyfire-10440-3-7v-600mah-batteries-blue-pair-91701?item=3)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on September 27, 2012, 11:31:10 am
Suddenly price shooted in dino & the current price is $60.39,can't find any working $10off coupon ,there is one i,e,.DDVALENTINE but don't know it is still active or not.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wartex on September 27, 2012, 12:50:28 pm
This topic seriously needs to die. The discussion has been beat to death. Yes, we get it, you all have UT61E. It's still a POS meter. It has turned into a UNI-T circle jerk.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 27, 2012, 02:18:50 pm
This topic seriously needs to die. The discussion has been beat to death. Yes, we get it, you all have UT61E. It's still a POS meter. It has turned into a UNI-T circle jerk.

...

Yes, we get it, you have more money to spend than us. Good for you, you still behave like a spoilt 12 year old, apparently.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on September 27, 2012, 03:14:00 pm
This topic seriously needs to die. The discussion has been beat to death. Yes, we get it, you all have UT61E. It's still a POS meter. It has turned into a UNI-T circle jerk.

(http://1-media-cdn.foolz.us/ffuuka/board/m/image/1293/17/1293178205627.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 27, 2012, 05:30:26 pm
POS?  ;) Really? Show me a 100$ meter that does 22000 counts with True RMS
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wartex on September 28, 2012, 04:24:59 am
POS?  ;) Really? Show me a 100$ meter that does 22000 counts with True RMS

For $100 I can get a used Fluke 8840 that will totally assrape this thing, with proper GPIB and RMS option. As for handhelds, this will fall apart on a construction site. So if you want a fancy handheld that's great for sitting on a bench, this is a meter for you. I bought an out of spec Fluke 289 on ebay for $180 and calibrated it for additional $70, way better investment. This meter is a gimmick.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on September 28, 2012, 05:13:49 am
This Uni-T UT61E is 60-65$, shipping included. 

Looking at eBay, I can't find that Fluke for 100$, only for $199 but my search skills may lack. Even if it were to be at 100$, we're talking almost twice the budget a user may have, and that's before calibration. The calibration itself costs more than what a single Uni-T 61E would cost!

Either way, it's NOT in the same category. Not handheld, not battery powered...

It's a meter for another segment of customers.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on September 28, 2012, 05:47:02 am
POS?  ;) Really? Show me a 100$ meter that does 22000 counts with True RMS

For $100 I can get a used Fluke 8840 that will totally assrape this thing, with proper GPIB and RMS option. As for handhelds, this will fall apart on a construction site. So if you want a fancy handheld that's great for sitting on a bench, this is a meter for you. I bought an out of spec Fluke 289 on ebay for $180 and calibrated it for additional $70, way better investment. This meter is a gimmick.

I don't think it's fair to compare these Fluke meters you mentioned with the UT-61E, for the following reasons:

1. Price - you simply can't compare a $50-60 meter (new and comes with all accessories) with something that costs $100-200+ used. They don't really compete in the same segment of the market.

2. Size - a bench meter takes up a much bigger footprint. Even the 289 is a much larger meter than the Uni-T. Not everyone has a spacious work bench. My "work bench" is only 2.5 x 1 ft (plus a shelf even shallower). Every square inch in my case counts. And no I can't afford any bigger space as properties in my country now cost US$1k+ per square FOOT!!

I completely agree that a Fluke would be a much more solid choice if one actually had the option to go for it, but in some cases they are simply not a viable choice. For hobbyists like myself, who doesn't need to carry a meter to a construction site and isn't really that fussy about 0.01% accuracy, something like the 61E would actually more than suffice.

Title: Re: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Tepe on September 28, 2012, 05:57:12 am
For $100 I can get a used Fluke 8840 that will totally assrape this thing, with proper GPIB and RMS option. As for handhelds, this will fall apart on a construction site.
You are shooting in all directions now. Bench meters, construction sites. Be coherent, man.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: David_AVD on September 28, 2012, 09:12:31 am
Heh, sounds like someone got up on the wrong side of the bench!   ;D

Don't like the thread?  Don't read it!  Very simple.   :)

This topic seriously needs to die. The discussion has been beat to death. Yes, we get it, you all have UT61E. It's still a POS meter. It has turned into a UNI-T circle jerk.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 28, 2012, 09:21:42 am
Heh, scratch that. A brand new 40-50$ (if you got it from china) meter with RS232, peak hold 22000counts and True RMS don't even talk about used
Found any meter with better value? And of course fluke 87s that go for 100$ is a scam operation
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on September 28, 2012, 01:25:26 pm
POS?  ;) Really? Show me a 100$ meter that does 22000 counts with True RMS

For $100 I can get a used Fluke 8840 that will totally assrape this thing, with proper GPIB and RMS option.

Good for you. I cannot get a Fluke 8840 at all, and I certainly can't afford one when spending half that much gets me a tool entirely appropriate for my usage.

Quote
As for handhelds, this will fall apart on a construction site.

Perhaps it will. I don't use it on a construction site.

Quote
I bought an out of spec Fluke 289 on ebay for $180 and calibrated it for additional $70, way better investment.

I don't have $180 and an additional $70 for a meter and even if I did, they aren't that cheap here. Yes, that's right, we don't all live in the US or their pet hat of a country with outrageously low prices for anything we want! Not much of an investment if you can't even make it.

Quote
This meter is a gimmick.

This meter is an affordable tool which works fine.

Shove off already. Nobody cares.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on September 28, 2012, 06:03:42 pm
For $100 I can get a used Fluke 8840 that will totally assrape this thing, with proper GPIB and RMS option.
No you can't. At the time of posting the cheapest 8840A on ebay is $127.11 after shipping. More than DOUBLE the price of this meter. I paid $45 shipped for mine. So in that case your meter is THREE times more expensive. So its not a fair comparison. Yeah a porshe is faster than a Hon da. You pay three times more for the porshe. It doesn't mean the Honda is a POS, just its a different intended market based on price point alone.

As for handhelds, this will fall apart on a construction site. So if you want a fancy handheld that's great for sitting on a bench, this is a meter for you.
Umm not really. I have a Fluke 116 sitting on my bench right now at work, long story on why a chem lab needs a Fluke 116. I have compared them both and I would take the Uni-T hands down. Sorry I know that may offend your delicate sensibilities but quite simply the Uni-T is built much better than the Fluke 116. The Fluke feels less solid, the plastic feels cheaper, the display on the Fluke sucks in comparison, the backlight is functionally useless it is so dim, etc. Yeah it has its nice rubber case but quite simply if I dropped them both off the bench I wouldn't be surprised if the Fluke broke, I would be surprised if the Uni-T did. I am saying this quite objectively, I can't speak for ANY other model of Fluke but the 116 is not amazing quality. Good yes, amazing no.

  I bought an out of spec Fluke 289 on ebay for $180 and calibrated it for additional $70, way better investment. This meter is a gimmick.
Hmm, not everyone needs or wants to spend $250 on a multimeter (now you are FIVE times the price of the Uni-T). I'm sure it made your e-penis feel bigger but other than that for most of us that meter is WAY WAY over kill. It's NOT a better investment its just throwing money down the drain on specs that we don't need. I could think of a lot of ways to spend the $200 difference that are a MUCH better investment for me. Lastly, a VICTOR meter is a gimmick. It's crap quality, doesn't meet the specs it claims etc. This meter is NOT a gimmick, its quite well made (its beats your precious Fluke quality in comparison to the 116) its been DOCUMENTED to meet the specs it claims. Not sure how that qualifies as a gimmick other than it doesn't inflate your e-penis.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: grumpydoc on September 28, 2012, 06:16:51 pm

                      ___________________________
                   /|  /|  |                          |
                   ||__||  |       Please don't       |
                  /   O O\__           feed           |
                 /          \       the trolls        |
                /      \     \                        |
               /   _    \     \ ----------------------
              /    |\____\     \     ||               
             /     | | | |\____/     ||               
            /       \|_|_|/   |    __||               
           /  /  \            |____| ||               
          /   |   | /|        |      --|               
          |   |   |//         |____  --|               
   * _    |  |_|_|_|          |     \-/               
*-- _--\ _ \     //           |                       
  /  _     \\ _ //   |        /                       
*  /   \_ /- | -     |       |                         
  *      ___ c_c_c_C/ \C_c_c_c____________             

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on September 28, 2012, 08:06:36 pm
What do you guys think about UT60H, did anyone tried it, is it fast and accurate like 61E?

http://item.taobao.com/item.htm?id=19161512480&ali_trackid=2:mm_14507416_2297358_8935934:1348858112_4k7_636123950 (http://item.taobao.com/item.htm?id=19161512480&ali_trackid=2:mm_14507416_2297358_8935934:1348858112_4k7_636123950)

I do need auto shut off and temperature measurement.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on September 28, 2012, 08:30:47 pm
If you need the temperature measurement get a dedicated digital thermometer. I say this having a fluke 116 which does temperature as well. A decent quality digital thermometer isn't cheap but the accuracy will be way better. Additionally, you will be able to use the proper thermocouple for the job based on the temperature range you are measuring. Thats just my opinion.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on September 28, 2012, 11:18:27 pm
If you are overseas don't use taobao or "englishtaobao" Use a taobao agent, much cheaper.

For me it works out so well and my agent is very trustable, only 7$ for the first 500g! and 4$ for the following 500g w/ EMS
And they pack so damn well, unlike DX!

Could you indicate their website ?
I found also one (several actually) but unlike yours the commission is 10% of the price of the product and the domestic shipping fee+ international shipping fee.
The prices are indeed very interesting.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on September 29, 2012, 01:05:58 am
My one is also 10% but there is no point in indicating unless you are in the same country as i am
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on September 29, 2012, 11:18:38 am
1>Let's say that  I purchased an item(in this case Ut 61e) & the product turns out defective or goes bad in 15days,then how would tabao agent can help in that case ?

2>Should tabao agent provides return shipping reimbursement like Dx ?

3>Is there any way that Tabao agent can cheat in any way ?
 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Bored@Work on September 29, 2012, 12:15:39 pm
1>Let's say that  I purchased an item(in this case Ut 61e) & the product turns out defective or goes bad in 15days,then how would tabao agent can help in that case ?

Really, these questions hardly make sense. A Taobao agent is no magical being. It is just some Internet business you can hire to act on your behalf. If an agent will help you even after the deal is done is anyone's guess. An agent will do what he likes to do. That could range from doing nothing to doing everything for you to get a replacement.

Quote
2>Should tabao agent provides return shipping reimbursement like Dx ?

An agent will do what he likes to do. That could range from providing nothing to providing everything for you to get a replacement.

Quote
3>Is there any way that Tabao agent can cheat in any way ?

In all the ways people can cheat. A Taobao agent is just some Internet business, typically located in China, doing business with foreign devils. They can pull all the tricks a business, an Internet business, and an Internet business in China can pull, especially when the customer is a foreign devils and has zero means to go after the agent. E.g. disappearing with your money over night, or sending you a brick instead of the multimeter.

That, and the seller might cheat on the agent. Using an agent means it becomes a three-party deal, and if any of the parties breaks the deal, there will be tears. How well an agent can or will protect you from the cheats of a malicious seller is something you will learn when it happens.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on September 29, 2012, 01:20:41 pm
From what I understood the agent does not protect you at all. He is just a middleman. The deal is as good as the seller is. You need to find a good seller with "diamond" or "crown" icons displayed. I was told that the red hearts are no good. To be honest I have not made my mind up yet. Yes it is a risky business for those who are not in China.
Some sellers offer 7 days money back warranty but you cannot send the product back in 7 days unless you pay UPS or DHL... Then there is the language barrier...
I am just buying abroad because MS8218 is not available locally any more.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on September 29, 2012, 09:13:42 pm
If you need the temperature measurement get a dedicated digital thermometer. I say this having a fluke 116 which does temperature as well. A decent quality digital thermometer isn't cheap but the accuracy will be way better. Additionally, you will be able to use the proper thermocouple for the job based on the temperature range you are measuring. Thats just my opinion.

Maybe I could live without a thermometer, but without the auto shut off no way. I need the instrument for the electronics repair shop only, no field work.
Overexpensive fluke's are out of the question.

I see you guys are looking for the good taobao agent. I searched the whole net, contacted many agents and I have found the absolute best and the cheapest one. I've done many taobao shopping via this agent and spent quite a few bucks.  Its called alsotao:  http://www.alsotao.com/ (http://www.alsotao.com/)
Trust me you won't regret them, they are true professionals. For registration on their site, some previous member would have to recommend you. Just say "Ratko" recommend me. I know them all there and they know me very good, I'm one of the oldest members. You also have the live chat there, there are 4 young girls on the customer support. The girl with the nick "Cindy" is absolutely the best and the most helpful one.
This is just my way to thank them for being such a honest and reliable agent.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on October 02, 2012, 09:28:43 pm
If you need the temperature measurement get a dedicated digital thermometer. I say this having a fluke 116 which does temperature as well. A decent quality digital thermometer isn't cheap but the accuracy will be way better. Additionally, you will be able to use the proper thermocouple for the job based on the temperature range you are measuring. Thats just my opinion.

Maybe I could live without a thermometer, but without the auto shut off no way. I need the instrument for the electronics repair shop only, no field work.
Overexpensive fluke's are out of the question.

I see you guys are looking for the good taobao agent. I searched the whole net, contacted many agents and I have found the absolute best and the cheapest one. I've done many taobao shopping via this agent and spent quite a few bucks.  Its called alsotao:  http://www.alsotao.com/ (http://www.alsotao.com/)
Trust me you won't regret them, they are true professionals. For registration on their site, some previous member would have to recommend you. Just say "Ratko" recommend me. I know them all there and they know me very good, I'm one of the oldest members. You also have the live chat there, there are 4 young girls on the customer support. The girl with the nick "Cindy" is absolutely the best and the most helpful one.
This is just my way to thank them for being such a honest and reliable agent.

Right they look good. You can buy nice old analog oscilloscopes with low shipment costs and new multimeters and anything small in size and weight on taobao. But the new company I have found in Germany offer cheaper prices for oscilloscopes and waveform generators.
Sorry this is not the right thread but I wanted post it here for the last time.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 03, 2012, 09:55:35 am
They looked nice but when I tried to make an A/C,it is showing 'System upgrade we suspended new user registration' for 5 days or so. >:(
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on October 03, 2012, 11:33:23 am
They looked nice but when I tried to make an A/C,it is showing 'System upgrade we suspended new user registration' for 5 days or so. >:(
They have live chat. If you tell them it is "Ratko" who recommended them they let you register :)))
Thank you Mr "Ratko".
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 04, 2012, 06:11:26 am
Thankx RICk,I succeded in creating my A/C by reffering Mr Ratko name,
Yes Long Live MR. RATKO
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 04, 2012, 10:10:10 am
To all Experienced taobao Buyers

Previously  T4P had posted this link:-

http://item.taobao.com/item.htm?id=15573161789&ali_trackid=2:mm_14507416_2297358_8935934:1347871879_4k9_375016240 (http://item.taobao.com/item.htm?id=15573161789&ali_trackid=2:mm_14507416_2297358_8935934:1347871879_4k9_375016240)

It is the cheapest available,but after reading what things to be considered before buying from Taobao,I found that it has 4 heats,I read that Diamonds are much better than Hearts & crowns(Gold) are best.


so I found these two links :-

Though its 3 Yuan more but still the reputation is better of these sellers

1>http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D8525801294 (http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D8525801294)
(My preffered)

-----------4 Diamond rating----Praise rate: 99.47%-----treasure number: 316-----The evaluation details 5
The turnover records 96------actually don't know what is meant by turnover records,evaluation details & trasure number
(210 Yuan)

2>http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D14727619956 (http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D14727619956)

--------3 Diamond rating----Rate: 99.37%---The evaluation details 80 The turnover records 66


Edit later I found these:-

3>http://translate.google.com/translate?act=url&depth=2&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D16418995332 (http://translate.google.com/translate?act=url&depth=2&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D16418995332)

4>http://translate.google.com/translate?act=url&depth=2&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D12988618456 (http://translate.google.com/translate?act=url&depth=2&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D12988618456)

Plz advise\assist which will be best & safest.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: nack on October 04, 2012, 10:23:00 am
What about all this Taobao stuff? Ebay doesn't seem to be that expensive either? At least you can actually understand whats on the page instead of some Chinese wizardry... ;-)

http://www.ebay.com/itm/130737816767;jsessionid=1858269375B9F734F403A5CBCA65A50F?ru=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D130737816767%26_rdc%3D1 (http://www.ebay.com/itm/130737816767;jsessionid=1858269375B9F734F403A5CBCA65A50F?ru=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D130737816767%26_rdc%3D1)

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Bored@Work on October 04, 2012, 11:10:37 am
What about all this Taobao stuff? Ebay doesn't seem to be that expensive either? At least you can actually understand whats on the page instead of some Chinese wizardry... ;-)

People thing it is cheaper, although it isn't really. All they should do it to apply that evil thing called math:

Code: [Select]
   UT-61E                               210 CNY  = 33.41 USD
+ domestic shipping fee                  10 CNY  =  1.59 USD  (estimated)
+ taobao agent, minimum service charge              5.60 USD  (yoybuy.com)
+ international shipping fee                       12.00 USD  (estimated, slow China Post with tracking)
=============================================================
                                                   52.00 USD


That eBay thing you mentioned: 55.37 USD

Assuming all other things equal (same chance of customs taking an interest, same PayPal currency conversion fee (which I am not sure about if you bay the agent in CNY...), same processing fee by the carrier, etc.), that eBay offer doesn't soud too expensive.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on October 04, 2012, 03:11:53 pm
Code: [Select]
   
             UT-61E                               210 CNY  = 42SGD
+ domestic shipping fee                  10 CNY  =  2SGD  (estimated)
+ taobao agent, minimum service charge              4.40SGD  (yoybuy.com)
+ international shipping fee                       7.00 SGD  (2-3 days, EMS)
=============================================================
                                                                   55.40SGD
If it was from DX i would be paying 71.04 at current exchange rates

Works out cheaper for me!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on October 04, 2012, 03:51:04 pm
To all Experienced taobao Buyers

Previously  T4P had posted this link:-

http://item.taobao.com/item.htm?id=15573161789&ali_trackid=2:mm_14507416_2297358_8935934:1347871879_4k9_375016240 (http://item.taobao.com/item.htm?id=15573161789&ali_trackid=2:mm_14507416_2297358_8935934:1347871879_4k9_375016240)

It is the cheapest available,but after reading what things to be considered before buying from Taobao,I found that it has 4 heats,I read that Diamonds are much better than Hearts & crowns(Gold) are best.


so I found these two links :-

Though its 3 Yuan more but still the reputation is better of these sellers

1>http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D8525801294 (http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D8525801294)
(My preffered)

-----------4 Diamond rating----Praise rate: 99.47%-----treasure number: 316-----The evaluation details 5
The turnover records 96------actually don't know what is meant by turnover records,evaluation details & trasure number
(210 Yuan)

2>http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D14727619956 (http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D14727619956)

--------3 Diamond rating----Rate: 99.37%---The evaluation details 80 The turnover records 66


Edit later I found these:-

3>http://translate.google.com/translate?act=url&depth=2&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D16418995332 (http://translate.google.com/translate?act=url&depth=2&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D16418995332)

4>http://translate.google.com/translate?act=url&depth=2&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D12988618456 (http://translate.google.com/translate?act=url&depth=2&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D12988618456)

Plz advise\assist which will be best & safest.
If you want a UNI-T UT61E buy it from "Jamesbondb" he ships very fast and he is the most reliable Chinese seller on ebay I came across so far. The others you have to beg them to give you a tracking number. And the last one I came across has problems shipping. "Shipped" 14 days after placing the order. Soon it will be one month and the items are still in "Jiangsu". I think I shall open a case on ebay or PayPal. I don't know the procedure exactly. That last transaction made me sick...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on October 04, 2012, 03:55:12 pm

1>http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D8525801294 (http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D8525801294)
(My preffered)

-----------4 Diamond rating----Praise rate: 99.47%-----treasure number: 316-----The evaluation details 5
The turnover records 96------actually don't know what is meant by turnover records,evaluation details & trasure number
(210 Yuan)

2>http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D14727619956 (http://translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&twu=1&u=http://item.taobao.com/item.htm%3Fid%3D14727619956)

Google Chrome is best for translation it offers a button for that.
Check that out:
http://myworld.ebay.com/jamesbondtb&ssPageName=STRK:MEFSX:SELLERID&_trksid=p3984.m1543.l2533 (http://myworld.ebay.com/jamesbondtb&ssPageName=STRK:MEFSX:SELLERID&_trksid=p3984.m1543.l2533)
He got bad comments too but I don't know. It would be best to buy form US but their shipping fees are too high.
I have just noticed he increased his price... 156 $! I bought it for 60 $ in summer. Is it inflation ?

0,1 % makes a big difference. The last one I had was at 99,7 still he is very bad.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on October 04, 2012, 04:11:04 pm
Funny how 95% rating sellers on aliexpress seem to be more reliable than 99.5% sellers on ebay ... Go figure!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on October 04, 2012, 04:14:26 pm
Do we need an agent for aliexpress or we are allowed to buy directly ?
I think we can buy ourselves.
And it is cheaper...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on October 04, 2012, 04:19:32 pm
Depends. It's not exactly cheap on aliexpress
I guess you didn't go onto aliexpress right? That's the global sister site of taobao
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on October 04, 2012, 04:35:21 pm
I haven't tried aliexpress yet. I was planning to buy the MS8218 but then I have watched today that video made by Martin Lorton (the second one)...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 04, 2012, 06:19:24 pm
What about all this Taobao stuff? Ebay doesn't seem to be that expensive either? At least you can actually understand whats on the page instead of some Chinese wizardry... ;-)

http://www.ebay.com/itm/130737816767;jsessionid=1858269375B9F734F403A5CBCA65A50F?ru=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D130737816767%26_rdc%3D1 (http://www.ebay.com/itm/130737816767;jsessionid=1858269375B9F734F403A5CBCA65A50F?ru=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D130737816767%26_rdc%3D1)


Yes ur right,but read the post carefully I didn't said that Ill purchase from Taobao its just for the estimation of the cost from Taobao & to see whether the price can go lower or not,but one thing is for sure Ill not buy from the ebay cuz the price is about  $55.37,instead I ll go to DD,current price is about 60.39 iirc,so I ll simply use 10% coupon & the price will go down to $54.35 i,e,' registered post with tracking & is much much safer than ebays'Economy Int'l Shipping',(non traceable),I think additional $2 is required for registered post ;).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 04, 2012, 06:34:14 pm
IIRC one of the member in this thread was searching MS8240D but can't find anywhere,well the good news is I found in our local store,they are selling at $120,Anyone knows how the accuracy of 8240 Dcompared with 61E,though it got more functions & utilizes the proceesor fully.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on October 04, 2012, 06:38:13 pm
same processor so i'll say also 0.1%
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 05, 2012, 08:18:48 am
Yes,same processor but don't no the reliability cuz in no place in the net there is  any single review or teardowns of MS8240D :o.

Oh yes Another seller is selling at $100 but both of them are not giving any warranties,though they said that they will test fully in front of me before selling.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on October 06, 2012, 12:30:10 pm

Right they look good. You can buy nice old analog oscilloscopes with low shipment costs and new multimeters and anything small in size and weight on taobao. But the new company I have found in Germany offer cheaper prices for oscilloscopes and waveform generators.
Sorry this is not the right thread but I wanted post it here for the last time.

What German company, can you give us a link please? I see used oscilloscopes on taobao, but it is not recommended to buy used things on taobao.
I was thinking of buying this, I can get it cheaper than on ebay, I need it mostly for digital electronic, just to see is crystal working and is there a digital signal running to the lcd screen and so on:  http://item.taobao.com/item.htmspm=a230r.1.10.11.b05429&id=13022376003 (http://item.taobao.com/item.htmspm=a230r.1.10.11.b05429&id=13022376003)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Tepe on October 06, 2012, 12:45:54 pm
What German company, can you give us a link please?
He means http://batronix.com (http://batronix.com)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on October 06, 2012, 07:46:16 pm
I see used oscilloscopes on taobao, but it is not recommended to buy used things on taobao.

Who does not recommend?
If you are in USA sure it is better to buy on ebay but sometimes they charge you 4x the price of the oscilloscope for overseas shipment. It does not make sense to buy such material on ebay for us. I think USPS is not that expensive (although that needs to be confirmed) it is just that the seller wants to make more profit by selling to an overseas buyer.
For example the guy (from USA using USPS) who sold me a soldering station charged me 77 $ for the shipment, whereas another one (also form USA and using USPS services) wanted to charge 144 $ of shipment cost for a similar weight. So clearly there is some abuse there.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on October 07, 2012, 12:40:56 pm
I see used oscilloscopes on taobao, but it is not recommended to buy used things on taobao.

Who does not recommend?
If you are in USA sure it is better to buy on ebay but sometimes they charge you 4x the price of the oscilloscope for overseas shipment. It does not make sense to buy such material on ebay for us. I think USPS is not that expensive (although that needs to be confirmed) it is just that the seller wants to make more profit by selling to an overseas buyer.
For example the guy (from USA using USPS) who sold me a soldering station charged me 77 $ for the shipment, whereas another one (also form USA and using USPS services) wanted to charge 144 $ of shipment cost for a similar weight. So clearly there is some abuse there.
I'm not in the USA. Buying used things on taobao you never know what you will get. Return shipping is too expensive. The seller can recognize that taobao agent is buying it from him and he can sent you a defective item, he estimate you can't return it. Buying used things is a gamble. I had that situation once and agent did help me but only because I was an old customer with many previous transaction, so he trusted me when I said that the item was defective.
I can recommended you YIHUA862D+ soldering station, it costed me 98$ with shipping vs. 140$ on ebay. It's popular in China. Only the solder temperature is not correct, but changing one resistor on the board fixed it, but slowed a little bit the heating time. Still, I'm sattisfied.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 15, 2012, 07:33:12 am
How about this  8),will solve the Rs 232 issue
http://dx.com/p/usb-to-rs232-adapter-with-usb-extension-cable-41cm-length-24799 (http://dx.com/p/usb-to-rs232-adapter-with-usb-extension-cable-41cm-length-24799)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on October 15, 2012, 09:26:52 pm
How about this  8),will solve the Rs 232 issue
http://dx.com/p/usb-to-rs232-adapter-with-usb-extension-cable-41cm-length-24799 (http://dx.com/p/usb-to-rs232-adapter-with-usb-extension-cable-41cm-length-24799)
Right, I got one from a local computer store but it requires some driver to be installed so my first connection attempt through a usb port failed:) I haven't tried again yet (it has also another adaptor which can be connected to the printer port I think).
Hey! While you are talking about the famous UT61E, today I have bought my first brand new Fluke 87 V! And I was so much excited I have also bought a used but apparently very "clean" (we shall see when it arrives) Fluke 83 for 81 $. And what is even more interesting is that those guys proposed to ship to my country with USPS 1st class mail which costs $19,5-$20. Not everybody accepts that though. I have joined the Fluke 87 V club today.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on October 17, 2012, 12:40:51 am
Someone find 61E about less $60 with shipping  HK or SG post? China air mail can not taking out multimeter almoust 1.5 mounth.(((
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on October 17, 2012, 01:02:27 am
Someone find 61E about less $60 with shipping  HK or SG post? China air mail can not taking out multimeter almoust 1.5 mounth.(((

I live in Hong Kong and can get hold of the UT 61E rather easily at a cost of around $40 including shipping from China to me. Depending on where you are, I should be able to ship one out through HK post (which is quite reliable and relatively quick comparing to China post), within your budget. I'm happy to help but obviously trust will be an issue as we are strangers to each other and merely fellow forum members. If you do want me to help let me know.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on October 17, 2012, 06:43:08 am
iloveelectronics
Thank you, but i will wait a little bit more for my order - today track was renewed, and I hope it will fly to me in nearest days.)))
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on October 18, 2012, 03:35:08 am
iloveelectronics
Thank you, but i will wait a little bit more for my order - today track was renewed, and I hope it will fly to me in nearest days.)))

You're experiencing this massive delay possibly partly due to the Chinese National Day holidays. It's a week-long public holiday for most people and businesses in mainland China starting Oct 1st. Other long holidays in China include the Lunar Chinese New Year in Jan/Feb and Labour Day in May. These are not good times to order anything from China (Hong Kong is different though).

To stay on topic, attached are 2 teardown pictures of my recently purchased UT-61E, with date of manufacture of 18 July 2012.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on October 18, 2012, 02:30:45 pm
Wow that's pretty new.
Looks the same as the 2011 batch. hmm
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: samgab on October 21, 2012, 03:21:42 am
Well the UT61E which I ordered from eBay more than a Month ago never turned up, so I emailed the seller. The seller claimed that China cutoms held it at customs because it has a battery in it, and has offered to refund me the ~50 I paid. I notice though:
1/ That seller has now put the price of this meter up to over $150, as it has gotten popular since I placed my order.
2/ I've ordered many, many items from China that have batteries inside them, and they've never been stopped by China customs...

Oh well, at least I'll get a refund, but I don't get to experiment with the UT61E and compare it to the Fluke 87V and 17b. Bummer.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on October 21, 2012, 04:19:43 am
Well the UT61E which I ordered from eBay more than a Month ago never turned up, so I emailed the seller. The seller claimed that China cutoms held it at customs because it has a battery in it, and has offered to refund me the ~50 I paid.

It is indeed official that Chinese customs don't allow batteries in the post (or even courier), but of course everybody is still sending them around. You probably just got unlucky and they spot checked your item or something.

I have actually ordered 3 of them from China and am planning to offer them for sale either through the buy and sell section of this forum or eBay next week. If you are still interested I can sell one to you for about $55 shipped (unfortunately I don't have the volume to match the ~$50 you paid). I will be selling them cheaper here on this forum than on eBay though, simply because of the eBay fees.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: prozac on October 21, 2012, 07:27:51 pm
1/ That seller has now put the price of this meter up to over $150, as it has gotten popular since I placed my order.

If you are talking about jamesbondtb, I orderd my UT61E from him as well and got it after about a month without any problems.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on October 21, 2012, 07:33:47 pm
Did you buy it at $150 ?
I remember vaguely that he had reduced his price to $56 for a short periode of time.
Another one mentioned by Martin Lorton is radioshop888. I have never bought from him.
I shall try to buy something on aliexpress.com to see how it works...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: prozac on October 21, 2012, 07:39:46 pm
No I bought it for $56, not sure why the price jumped up to $156. He is probably just out of stock.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on October 21, 2012, 09:12:33 pm

Another one mentioned by Martin Lorton is radioshop888. I have never bought from him.


Yeah, I bought mine almost a year ago from radioshop888 on eBay.  65$ with free shipping at that time.

Here's the pen as proof :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on October 23, 2012, 09:16:22 am
To stay on topic, attached are 2 teardown pictures of my recently purchased UT-61E, with date of manufacture of 18 July 2012.
Wow, is it 555-timer in picure 2?

I was ordered and payd UT-61E on 2 sepember (!), 8.09 posted, last mark 27.09 - Import ZHEJIANG.:(

2All
Yes, many parcels sends China Air Mail has back to sender, and most bad for that - many byers even not aware of it.
But, LCR meter with 9v battery - come to me in 1 mounth, by HK post without track.

I shall try to buy something on aliexpress.com to see how it works...
Better don't. My undelivered 61E was ordered on aliE. Many sellers there not respond for parcel, thay can feed you promices like "tomorrow it will come to you, go check on post" and many alse, then suddenly "I'm sorry my dear friend, the package was back to me. Will I resended to you again?" and thats after mount of promices??? Others will remain silent until the dispute threatened to, and then they find out that the package did come back to him.
Unless of course you will not find a trusted vendor who sends HK or SG post.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on October 23, 2012, 10:30:47 am
Wow, is it 555-timer in picure 2?

It's not a 555 timer. It's an AD737 true RMS to DC converter.

Quote
I was ordered and payd UT-61E on 2 sepember (!), 8.09 posted, last mark 27.09 - Import ZHEJIANG.:(

Where did you order it from? I think you should ask the seller for an update and possibly a refund. You've waited long enough.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on October 23, 2012, 11:09:44 am
iloveelectronics
Yes, I write him week after, because trecker says "import ZHEJIANG". He answer "possibly" and resend without battery, and 16.10 was export.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mehran on October 23, 2012, 08:18:38 pm
got my ut61e the other day: it looks a bit different inside from the one shown at the start of the thread:(http://imageshack.us/a/img9/4054/img20481s.jpg) (http://imageshack.us/photo/my-images/9/img20481s.jpg/)

(http://imageshack.us/a/img7/8734/img20471c.jpg) (http://imageshack.us/photo/my-images/7/img20471c.jpg/)

think my one is rev 8? as you can see there is a bit of a bodge with two caps on top of each other... on the plus side the resister network fits the board.

sadly the red lead that came with mine is faulty. it give between 50 ohms to few mega ohms with the flexing of the cable. so will need to buy a new set.


I have always used manual ddm, so finding the auto ranging a bit hard to get used to...but it does feel will built.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 25, 2012, 12:07:02 pm
Recently purchased one from Dino Direct for an amazing price of $50.351 with tracking number  8).

@iloveelectronics
Where can I find the date of manufacture ?
The back sticker is displayed as
(QB/441900 17 10489-2011)

Does that means that the manufacturing date is in 2011  :(,so should I return it back to  DD (if they provide return shipping fee) & get a new one,


the meter is working fine,but some resistor looked older !

so is the older meter worth it or sending & getting a new one will be better ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on October 25, 2012, 12:36:32 pm
@iloveelectronics
Where can I find the date of manufacture ?
The back sticker is displayed as
(QB/441900 17 10489-2011)

so is the older meter worth it or sending & getting a new one will be better ?

You should find a warranty card inside the package, with a date stamped on it.

If the meter works fine I don't think it's necessary to return. You'll more than likely have to pay for the return shipping, which I don't think is worth it.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 25, 2012, 01:32:48 pm
No I can't find any warranty card inside,

I can find various rubbish things like:-
1>Advertisement cards,
2>Spring festival post cards,
3>Christmas cards,thanks giving cards,
4>Halloween post card,
5>Operating manual
&
Invoice

They actually have done it very cleverly,what do U think ?
I don't even know my product is original or clone,
so what should I do now ?

One thing is for sure is that they have done this deliberately
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on October 25, 2012, 01:52:04 pm
No I can't find any warranty card inside,


You can take a look at the picture (2nd one) of my eBay auction here: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200837432118 (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200837432118)

This should be all the content in the original package. That card with the date stamped on it is the warranty card, it's only valid in China though.

I guess you can try to contact them and ask about it, and maybe you can ask if they would accept a return on this basis. But for me personally if the meter works fine I wouldn't bother.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 25, 2012, 02:29:26 pm
@iloveelectronics

Yes thanks for the link,Yes I confirm that I didn't got the warranty card.

Plz can u say whats written in the backside of the meter(sticker-the last four digits)
Is it 2011 or 2012 ?

Yes Ill talk to DD customer support team for sure.



@All
I can see some ghost readings without connecting the probes
1>V(DC)---.0001
      (AC)----.0007

2>mV(DC)---(-200 to 30)
          (AC)---(35 to 2)

3>Capacitance---(.065nF stagnant)

Are those specs are in normal ranges ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on October 25, 2012, 03:41:02 pm
@iloveelectronics

Yes thanks for the link,Yes I confirm that I didn't got the warranty card.

Plz can u say whats written in the backside of the meter(sticker-the last four digits)
Is it 2011 or 2012 ?

Yes Ill talk to DD customer support team for sure.



@All
I can see some ghost readings without connecting the probes
1>V(DC)---.0001
      (AC)----.0007

2>mV(DC)---(-200 to 30)
          (AC)---(35 to 2)

3>Capacitance---(.065nF stagnant)

Are those specs are in normal ranges ???

I have the exact same number on the sticker as yours QB/441900 17 10489-2011, and the serial number underneath it is C120312601. If you have a similar serial number it's probably from same or similar batch.

Those readings look very normal to me, I don't think you have anything to worry about.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on October 25, 2012, 04:10:22 pm
Don't worry about the readings.
My meter from DD didn't have a batch code either  ??? But my one from DX has ...hmm, but they look the same internally, down to the "bodged-on" solder  ???
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ModemHead on October 26, 2012, 03:23:22 am
Could I ask a favor of any interested UT61E owners?  Set your meter to measure AC voltage, with auto-ranging on.  Probe a DC voltage of say about +10V or more.  What does the meter do?

The unit I have here will 'go crazy' in this situation.  It flashes random digits, beeps erratically, and the bar graph jumps around.  It will measure ACV correctly only if any DC component is less than about +10V, or if the correct range is selected manually.  Negative DC offsets do not seem to bother it.  All other measurement functions of this unit appear to be normal.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on October 26, 2012, 03:44:19 am
Yup, it does the same on my unit. But if I drop the DC voltage down below 10V and then back up again, it doesn't go crazy anymore.

Could I ask a favor of any interested UT61E owners?  Set your meter to measure AC voltage, with auto-ranging on.  Probe a DC voltage of say about +10V or more.  What does the meter do?

The unit I have here will 'go crazy' in this situation.  It flashes random digits, beeps erratically, and the bar graph jumps around.  It will measure ACV correctly only if any DC component is less than about +10V, or if the correct range is selected manually.  Negative DC offsets do not seem to bother it.  All other measurement functions of this unit appear to be normal.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ModemHead on October 26, 2012, 04:04:41 am
Yup, it does the same on my unit.
Thanks for the report!

But if I drop the DC voltage down below 10V and then back up again, it doesn't go crazy anymore.
Yeah, I checked with a function generator.  If the DC offset goes up slowly it's OK.  But if you introduce an offset quickly, or if you probe something already containing sufficient DC offset, it goes bonkers.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 26, 2012, 12:38:21 pm
Thankx to  iloveelectronics & T4P for quick responses,now I am little-bit relieved

@iloveelectronics it seems the batch of Ur's & mine are same but my serial no is C120312576 so mine must be produced day before Urs or in the same day & in between 24 more produced IMO.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on October 26, 2012, 03:04:22 pm
C12 = 2012.
My one is C110346024 from DX and C110483549 But oddly the one on the DX one has a weird sticker : QB/441900 17 10489-2011, from DX?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on October 26, 2012, 06:39:30 pm
Yup, it does the same on my unit.
Thanks for the report!

But if I drop the DC voltage down below 10V and then back up again, it doesn't go crazy anymore.
Yeah, I checked with a function generator.  If the DC offset goes up slowly it's OK.  But if you introduce an offset quickly, or if you probe something already containing sufficient DC offset, it goes bonkers.

My guess is that it has somethign to do with the rapid change from zero to whatever the voltage ends up being is too high and sends something into oscillation.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 26, 2012, 07:54:26 pm
C12 = 2012.
My one is C110346024 from DX and C110483549 But oddly the one on the DX one has a weird sticker : QB/441900 17 10489-2011, from DX?


Perfectly same as me  :o,I think it can only be explained by Uni-T guys  ???
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ModemHead on October 26, 2012, 10:36:18 pm
My guess is that it has somethign to do with the rapid change from zero to whatever the voltage ends up being is too high and sends something into oscillation.
Hard to avoid a rapid change from zero when you put the probes on something.

I've also noted that the AC mV range produces incorrect readings in the presence of a DC offset greater than about 2V.  It does not go crazy, it just displays a value that is completely wrong, eg. an order of magnitude low.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on October 28, 2012, 09:43:24 am
Found this nifty gadget,

http://www.voltagestandard.com/DMMCheck.html (http://www.voltagestandard.com/DMMCheck.html)

for those who wants to caliibarate thier DMM,though not necessary for Ut61E cuz already very tuned,but because pots are their it is possible

for more info visit this :-

http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.messerforum.net%2Fshowthread.php%3F100485-Multimeter-pr%25FCfen-kalibrieren-justieren%26p%3D802825%26viewfull%3D1%23post802825&act=url (http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.messerforum.net%2Fshowthread.php%3F100485-Multimeter-pr%25FCfen-kalibrieren-justieren%26p%3D802825%26viewfull%3D1%23post802825&act=url)






Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on November 01, 2012, 01:03:24 pm
Finally I got my UT-61E. How can I test it on the correct performance, make sure that it is fully working and correctly measure?
There is another more simple multimeter Victor 81D.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on November 01, 2012, 03:15:30 pm
Finally I got my UT-61E. How can I test it on the correct performance, make sure that it is fully working and correctly measure?
There is another more simple multimeter Victor 81D.

You can of course check it against your Fluke 87 V ;D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on November 01, 2012, 04:23:44 pm
Why not? 8)
(http://www.embed.com.ua/wp-content/uploads/2012/07/Parameters.gif)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on November 01, 2012, 05:11:51 pm
So it's accurate.

Only 1000uF is different, but then again at capacitance the error margin is 3%+5 counts .. .that would be about 30uF at 1000uF ... and I think the Fluke is also about 2% at that large capacitance value, so you can't say it's faulty.

Everything else seems to be a few counts above or below, certainly within the specified tolerances.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ivanko1 on November 01, 2012, 05:23:15 pm
I get this from little review http://www.embed.com.ua/raznoe/multimetr-uni-t-ut61e-iz-kitaya/ (http://www.embed.com.ua/raznoe/multimetr-uni-t-ut61e-iz-kitaya/)

Does 61E not have auto off? There signin (S) - Data Processing? No cable plugin, how it turn off?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on November 01, 2012, 05:38:06 pm
The data logging is always on , so there is no auto power off.

You can solder a few wires inside and make auto power off work, there is a hack published on this forum, possibly on the first page of this thread ... not sure not, it may be the other hack with the backlight.
Either way, it's on this forum, in this thread or another thread.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: TorqueRanger on November 02, 2012, 11:20:36 pm
Is it possible to upgrade the safety features of the meter without compromising the accuracy of the meter ??
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on November 03, 2012, 05:00:08 am
Yes.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on November 03, 2012, 07:57:10 am
Yes.


How ?

For me the main concern is if probes are inserted in wrong slots when measuring.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on November 03, 2012, 08:08:22 am
Did anyone figured out how to activate the auto off feature  ::)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on November 03, 2012, 08:44:32 am
I tried to measure the amp of my flashlight(TF-3T6)with UT-61E,but it cannot measure it,neither it's powering up the flashlight but my $10 DMM is measuring fine & displaying around 2.5amps.
What's the reason ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on November 03, 2012, 09:26:34 am
Check your 10A fuse, you may have blown it.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Soertier on November 03, 2012, 09:27:35 am
I tried to measure the amp of my flashlight(TF-3T6)with UT-61E,but it cannot measure it,neither it's powering up the flashlight but my $10 DMM is measuring fine & displaying around 2.5amps.
What's the reason ?

Test leads may have high resistance (do not forget this type of flashlights use relatively low voltages and high currents) or you didn't do something right, wrong jacks, shorted the meter,etc.
Owning the UT61E, I would not recommend using the leads which my UT61E came with (Don't know about yours) for high currents at low voltages.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on November 03, 2012, 10:55:05 am
Did anyone figured out how to activate the auto off feature  ::)

Have a quick search on the forum..
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on November 03, 2012, 12:24:46 pm
The leads are pretty good actually.
Just remember to use IPA and clean the tip every now and then in a humid environment
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on November 05, 2012, 03:33:21 am
 I won a few auctions on ebay from a particular seller. I got 25x 578pF (yep 0.578nF) 1% Silver Mica capacitors, 50x WIMA 0.22uF 250V 10% and 25x 3.6uH inductors for <$18 shipped from the same seller.

Well I decided to push things a little harder ;D. In particular the silver mica 1% were what I was interested in. Particularly because they are low value high precision (relatively) caps and there was a good enough qty that I could test them all and get an acceptable precision in my measurements.

I tested all capacitors two ways: using the test leads (using the Rel function) and using the adapter (using the Rel function). I reset the relative value between each measurement (essential for the test leads, not so much for the adapter). The reported value of 578pF +/- 1% means that the measurements should fall between 0.573nF and 0.584nF.

Now for the results:
The measurement using test leads are listed first while the measurements using the adapter are in parentheses.
 #1 - 0.584nF(0.582nf)     #11 - 0.582nF(0.580nF)     #21 - 0.581nF(0.580nF)
 #2 - 0.582nF(0.581nF)     #12 - 0.580nF(0.578nF)     #22 - 0.581nF(0.580nF)
 #3 - 0.581nF(0.581nF)     #13 - 0.578nF(0.578nF)     #23 - 0.584nF(0.584nF)
 #4 - 0.582nF(0.580nF)     #14 - 0.583nF(0.582nF)      #24 - 0.585nF(0.584nF)
 #5 - 0.584nF(0.584nF)     #15 - 0.581nF(0.580nF)     #25 - 0.579nF(0.578nF)
 #6 - 0.584nF(0.582nF)     #16 - 0.584nF(0.582nF)
 #7 - 0.581nF(0.580nF)     #17 - 0.580nF(0.580nF)
 #8 - 0.579nF(0.578nF)     #18 - 0.583nF(0.580nF)
 #9 - 0.584nF(0.584nF)     #19 - 0.584nF(0.582nF)
 #10 - 0.580nF(0.580nF)     #20 - 0.585nF(0.584nF)

Average Value  - 0.582nF(0.58096nF)
Percent Error from Reported Value: 0.692042%(0.512111%)
The results range from 0%-1.0% of the reported value.

This is incredible, the listed accuracy for this range is +/- 3.0%+5 counts. Enough said!

A few things I learned from this. One, as the manual says the adapter is MUCH more reproducible and appears to be a bit more accurate. Using the adapter I measure the same cap 10 times through out the test and every time it returned the same value. Using the test leads it was always +/- 1 count. Second, the adapter works even though you don't plug it into the COM port. One end plugs into the cap,volt,ohm,etc. port the other actually plugs into the mAuA port.

I then tested the 50x 0.22uF WIMA 10% caps, just to see how they do.

I'm not going to bother to list out 50 values. I tested the adapter for the first 10 and there was NO difference between the adapter readings and the test lead readings. Additionally, these are high enough in capacitance that the relative function is not necessary.

Now to see how they did. The average value was 0.221553uF which is an error of only 0.706% from the reported value! Keep in mind this test range is still 3.0%+5 counts accuracy The results have a much higher variation ranging from -5.77%-5.59% of the reported value. That is still well within the +/-10% reported for the caps themselves.

This meter just continues to impress me!

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on November 05, 2012, 04:16:34 am
Also the meter is sub-$50 again at DinoDirect!

$55.35 is the current price (with free shipping). Add coupon code DEAL10DD to drop it to $49.85 and if you are a Fatwallet member. You can get 5% FWCB. Which makes the final price $47.36. HEHE! Merry X-Mas ;D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on November 05, 2012, 06:28:09 am
UNI-T is probably the only DMM mfr i know so far that provides such a adaptor  :P
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on November 05, 2012, 07:18:45 am
UNI-T is probably the only DMM mfr i know so far that provides such a adaptor  :P

It's kind of funny because I originally though it was more or less useless for our meter. It didn't seem to match our hole configuration. I figured it was mainly for HFE and temp measurements and maybe testing smd parts. Clearly, I should have known otherwise because they would have cut it long ago to save costs. After using it this evening for the low capacitance measurements I have to say it made that job a piece of cake. Using the test leads was a pain in the rear. Constantly re-zeroing...oh crap I moved the leads it now reads -0.002...gotta re-zero again...looks better...move to the capacitor...dang it now it reads 0.001...maybe if I hit REL with my toe while holding the leads (yes that thought actually crossed my mind at one point ;D).  Some of the measurements using the test leads had me re-zeroing around 4-5 times before I was satisfied the innate capacitance was accounted for.  With the adapter, zero it out, insert cap, let it sit for a second, done. I have a new affinity for that little thing.


After discovering that in the manual and seeing how useful it is I decided to read the rest of the manual. I'm actually discovering a few more interesting/humerous things about the UT61E by reading the manual:

It suggests using the adapter for more accurate high resistance measurements (>1Mohm).

Then there is this odd gem:UT61E:Measuring Audio frequency,if the input voltage is more than 15 volt. the meter will simulate the sound in same frequency. Yes that random period after volt is in the manual as well.

To clean the terminals with cotton bar with detergent, as dirt or moisture in the terminals can affect readings I'm not even sure what this means exactly. I know those words are english but...

Take out the battery when it is using for a long time. :P

Accuracy is guaranteed for 1 year.  :) What happens if it falls out of accuracy, lol. Though based on how it is behaving I'd believe it would hold cal for a year.

They keep talking about measuring 1000V but the damn thing is fused for 250V! I really don't get that mess.

They claim around 50pF residual capacitance and I have to say that was pretty close to right. (I think mine was 58pf). Add the adapter and it jumps to 66pF, with test leads it was closer to 80pF (but it varied greatly on how the leads were oriented with each other.

It's funny I keep thinking this meter can't surprise me anymore and it does again and again.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on November 05, 2012, 07:54:53 am
They keep talking about measuring 1000V but the damn thing is fused for 250V! I really don't get that mess.

Only a problem for current, and easily fixed.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on November 05, 2012, 08:03:51 am
They keep talking about measuring 1000V but the damn thing is fused for 250V! I really don't get that mess.

Only a problem for current, and easily fixed.

Doh, I'm a fool on that one. Thanks for correcting me.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on November 05, 2012, 09:33:14 am
To clean the terminals with cotton bar with detergent, as dirt or moisture in the terminals can affect readings
Not exactly english but they tried their best to translate, i've seen worst manuals from some "top" companies on their low-end products which are clearly some rebadged stuff (Or re-fried sick if you prefer)
Interpreted as : Clean the terminals with a cotton bar with some detergent periodically as dirt or moisture buildup can affect readings ... though i don't agree with the detergent part.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: WhiteFireDragon on November 06, 2012, 09:38:06 am
Also the meter is sub-$50 again at DinoDirect!

$55.35 is the current price (with free shipping). Add coupon code DEAL10DD to drop it to $49.85 and if you are a Fatwallet member. You can get 5% FWCB. Which makes the final price $47.36. HEHE! Merry X-Mas ;D
Hey you just posted this yesterday, but price has doubled. It shows as $98.99 from dinodirect. Am I missing something here?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on November 06, 2012, 10:08:37 am
Also the meter is sub-$50 again at DinoDirect!

$55.35 is the current price (with free shipping). Add coupon code DEAL10DD to drop it to $49.85 and if you are a Fatwallet member. You can get 5% FWCB. Which makes the final price $47.36. HEHE! Merry X-Mas ;D
Hey you just posted this yesterday, but price has doubled. It shows as $98.99 from dinodirect. Am I missing something here?

I see 2 listings there, one for $89.99 and the other 98.99. Anyway, they were probably just clearing out some older stock (with older dates of manufacture) at the very low price and I guess now those are all gone.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on November 06, 2012, 12:34:52 pm
If you need to pay more than $60 for a UT61E, it doesn't look as good. It isn't worth that price unless you need the PC connection and at that it is still not a great buy. Without back light and auto power off it doesn't compete at $90 when you can get an Amprobe AM270 for the same price which has much better input protection, back light, auto power off, and basically the same accuracy. The UT61E does have 22000 count though instead of 5000.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on November 06, 2012, 02:40:04 pm
Of course not.
Just stick to DX
http://dx.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306?item=2 (http://dx.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306?item=2)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on November 06, 2012, 05:33:53 pm
Of course not.
Just stick to DX
http://dx.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306?item=2 (http://dx.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306?item=2)

Or AliExpress http://www.aliexpress.com/item/UNI-T...548923745.html (http://www.aliexpress.com/item/UNI-T...548923745.html) ($51 shipped to the USA).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick on November 06, 2012, 07:47:19 pm
Of course not.
Just stick to DX
http://dx.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306?item=2 (http://dx.com/p/ut61e-2-6-lcd-digital-multimeter-red-black-1-x-9v-6f22-battery-113306?item=2)

Or AliExpress http://www.aliexpress.com/item/UNI-T...548923745.html (http://www.aliexpress.com/item/UNI-T...548923745.html) ($51 shipped to the USA).

If you buy from China, buy from Hong Kong. Shipping from there is way faster and you can track it better. I have just realized that.
I shall try to work with HK sellers as much as possible from now on.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on November 13, 2012, 02:21:28 pm
Happy Diwali to all :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on November 13, 2012, 06:44:21 pm
Happy Diwali to all :)

Not quite sure why you posted that in here but happy Diwali mate! ;D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on November 13, 2012, 06:58:56 pm
Festival of loud bangs..........

Started on 1 Nov and will continue till Dec.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: bitwelder on November 18, 2012, 09:35:30 am
Do you think it would be possible (and make sense) to fix/upgrade the input section of this meter, e.g. by replacing the split input jacks with solid ones, and perhaps adding some MOVs or other protections ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on November 18, 2012, 09:59:35 am
Why do you need to "upgrade" the split jacks? They work fine for what they are.
MOVs into the Gas discharge tubes footprint is a good idea if i remember that's what monkeh did
As well as the fairly obvious one is to upgrade the fuses. I am getting a box of 6.3x32 1000V siba 30-50kA fuses for 500mA and 10A (Clearly for my upcoming MS8218, 500V for the FF10A) as well as 10x38 Siba 30kA (the ones agilent uses) 1000V for 10A
Odd that a smaller fuse has a much higher breaking capacity rating at the same voltage while being cheaper
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on November 21, 2012, 11:26:17 am
Apparently there is no problem in my 61E,but after opening it I found that there are loads of non shiny surface,so if I heat the solder points and apply rosin,could it be  be better for accuracy or can it hamper the calibration ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fraser on November 21, 2012, 05:07:58 pm
Welcome to the horror that unleaded solder is !  ;)

Unleaded solder can look very dull and almost a 'dry joint' in its appearance. I still use 2% silver loaded leaded 60/40 solder and always have nice shiny joints. Don't worry about the dull look in your meter, it is normal unleaded ROHS compliant (read 'crap') solder and should be OK. Rosin will not help as teh solder is the problem not the flux.

Kind Regards

Fraser
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on November 21, 2012, 05:10:23 pm
It ain't 60/40 if it's got 2% silver in it!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on November 21, 2012, 05:40:48 pm
Welcome to the horror that unleaded solder is !  ;)

Unleaded solder can look very dull and almost a 'dry joint' in its appearance. I still use 2% silver loaded leaded 60/40 solder and always have nice shiny joints. Don't worry about the dull look in your meter, it is normal unleaded ROHS compliant (read 'crap') solder and should be OK. Rosin will not help as teh solder is the problem not the flux.

Kind Regards

Fraser
Hey there mate! Been some time since i've seen you around, there's a new lead-free out there that could be considered though, it's Sn42Bi58 and if i remember it's melting point is 138C  >:D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: nukie on November 22, 2012, 01:33:19 pm
You don't need silver in 60/40 solder for a shiny joint. Quality solder manufactured from high purity material coupled with proper flux makes shiny mirror joints.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on November 22, 2012, 03:10:08 pm
My 61E arrived today.

In the manual I see warning: "To avoid personal harm, do not attempt to input higher than 30V rms tested frequency voltage."

I want to ask can I measure frequency of the 220V wall outlet?
I'm confused here.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on November 22, 2012, 03:12:35 pm
My 61E arrived today.

In the manual I see warning: "To avoid personal harm, do not attempt to input higher than 30V rms tested frequency voltage."

I want to ask can I measure frequency of the 220V wall outlet?
I'm confused here.

Yes, press the yellow button while in VAC.

I really don't see why people want to measure that all the time though.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on November 22, 2012, 03:54:50 pm
It had successfully measured that the 1kHz/1MHz probe test outlet in my Hameg HM204-2 vintage scope had drifted to 1.16MHz with UT61E in Hz mode (2Vpp test outlet). I was sure I had adjusted the horizontal to proper cal along with the vertical when I got that scope broken years ago from Epay and fixed it, but the test signal it looked bit narrow on screen now. Then the same 1.16MHz was verified on the Rigol. So its Hz function is reliable enough I think. I was ready to open the beast again and dive in but a handy check with that meter gave me the right clue.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on November 22, 2012, 03:59:22 pm
Only time will be with a cheap genset when you want to see what the frequency is because it is unstable.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on November 22, 2012, 04:26:59 pm
Only time will be with a cheap genset when you want to see what the frequency is because it is unstable.

Just run a quick test. Can follow my gen well in Hz mode at 200mV RMS (high Z ampl=displayed X2). It loses it beyond 460kHz if in ACV yellow shift Hz mode. 50kHz if signal is 50mV RMS.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on November 22, 2012, 04:35:23 pm
So the Hz mode advantage is it is more sensitive in lower amplitudes. ACV Hz mode needs significantly more signal level to keep track progressively as the frequency goes up. But it can take more than 30V AC.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on November 22, 2012, 04:38:15 pm
My 61E arrived today.

In the manual I see warning: "To avoid personal harm, do not attempt to input higher than 30V rms tested frequency voltage."

I want to ask can I measure frequency of the 220V wall outlet?
I'm confused here.

Yes, press the yellow button while in VAC.

I really don't see why people want to measure that all the time though.

Can I also turn the knob to Hz/% position and then also test the wall outlet frequency? Will it do any harm to the instrument?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on November 22, 2012, 04:51:29 pm
My 61E arrived today.

In the manual I see warning: "To avoid personal harm, do not attempt to input higher than 30V rms tested frequency voltage."

I want to ask can I measure frequency of the 220V wall outlet?
I'm confused here.

Yes, press the yellow button while in VAC.

I really don't see why people want to measure that all the time though.

Can I also turn the knob to Hz/% position and then also test the wall outlet frequency? Will it do any harm to the instrument?

I believe the manual answered your question already.

Why do you even want to check the mains frequency? I assure you, it's not going anywhere.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on November 22, 2012, 05:04:18 pm

Can I also turn the knob to Hz/% position and then also test the wall outlet frequency? Will it do any harm to the instrument?

I believe the manual answered your question already.

Why do you even want to check the mains frequency? I assure you, it's not going anywhere.
[/quote]

I don't know really , just for the info. I turned the knob to Hz/% and into the AC mains, just for the split of a second and there was some fast beep sound from the instrument and i disconent it immediately. He appairs to work normal, on the V switch is showing 50Hz.  Is it protected for the case of a misusing? 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on November 22, 2012, 05:05:57 pm

Can I also turn the knob to Hz/% position and then also test the wall outlet frequency? Will it do any harm to the instrument?

I believe the manual answered your question already.

Why do you even want to check the mains frequency? I assure you, it's not going anywhere.

I don't know really , just for the info. I turned the knob to Hz/% and into the AC mains, just for the split of a second and there was some fast beep sound from the instrument and i disconent it immediately. He appairs to work normal, on the V switch is showing 50Hz.  Is it well protected for the case of a misusing?
[/quote]
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on November 22, 2012, 05:08:31 pm
I don't know really , just for the info. I turned the knob to Hz/% and into the AC mains, just for the split of a second and there was some fast beep sound from the instrument and i disconent it immediately. He appairs to work normal, on the V switch is showing 50Hz.  Is it protected for the case of a misusing?

No, it's playing the mains through the speaker. Yes, really.

It'll do that for a short while before it breaks. Don't use that switch position above 30V.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on November 22, 2012, 05:29:45 pm
The manual says that if the input voltage is high enough, it will try to play the waveform on the internal piezo speakers.

The manual also says you SHOULD NOT use the Hz position with more than 30V rms, but this is for safety reasons.  It doesn't say the meter will fail.

Martin tested the meter on his Youtube channel and tested the Hz on mains 240v AC and it didn't die, but naturally it doesn't like it, that switch position is for low voltage stuff.  To measure AC frequency, you go to V and press the yellow button.

Martin's review is below.. bear with him as he does some minor mistakes but he corrects himself in the following videos. He did these reviews straight as he gets the meter without checking the manual, so some things were confusing to him.
I personally like this style, but some may not be very patient.


Part 1  design, lcd screen, dc voltage, resistors, diodes, capacitors etc

Multimeter Review / buyers guide: Part 1 - UNI-T UT61E (https://www.youtube.com/watch?v=Bz6CYDRl1M8#ws)

Part 2  data logging (own software and ultradmm) , ac voltage, frequency voltage

Multimeter Review / buyers guide: Part 2 - UNI-T UT61E (https://www.youtube.com/watch?v=5YbbbgbJK9I#ws)

Part 3 Insides, battery consumption

Multimeter Review / buyers guide: Part 3 - UNI-T UT61E (https://www.youtube.com/watch?v=P_h27mRCH6s#ws)

Part 4  Cold / Hot tests (how stable and accurate remains when outside the specified operating temperature) ,  calibration

Multimeter Review / buyers guide: Part 4 - UNI-T UT61E (https://www.youtube.com/watch?v=q9n0scdsung#ws)


Really, you guys should read the manual.. it's mixed with information for the other meters in the series but it's not that hard to read and understand. You can get the English version from uni-t's site: http://www.uni-trend.com/manual2/UT61English.pdf (http://www.uni-trend.com/manual2/UT61English.pdf)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on November 22, 2012, 05:41:00 pm
The manual also says you SHOULD NOT use the Hz position with more than 30V rms, but this is for safety reasons.  It doesn't say the meter will fail.

It will damage components if you leave it connected to that high a voltage for long. Check the schematic. Far as I'm aware, that will break either the capacitors or the chip itself in pretty short order.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dimitrioptimus on November 22, 2012, 07:50:07 pm
Welcome to the horror that unleaded solder is !  ;)

Unleaded solder can look very dull and almost a 'dry joint' in its appearance. I still use 2% silver loaded leaded 60/40 solder and always have nice shiny joints. Don't worry about the dull look in your meter, it is normal unleaded ROHS compliant (read 'crap') solder and should be OK. Rosin will not help as teh solder is the problem not the flux.

Kind Regards

Fraser

thanks for the response

"read crap" did U meant real,l in place of r ? :-//

so its relieving that its normal to see nonshiny surface for unleaded solder.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on November 23, 2012, 05:43:46 am
Anyone who does that when the manual clearly states not to be used above 30V deserves to get blown up  :-+
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: bitwelder on November 23, 2012, 09:29:15 am
It will damage components if you leave it connected to that high a voltage for long. Check the schematic. Far as I'm aware, that will break either the capacitors or the chip itself in pretty short order.
Can you guesstimate what that 'short order' would be? Few seconds? Minutes? More?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dr_p on November 23, 2012, 11:06:41 am
Anyone who does that when the manual clearly states not to be used above 30V deserves to get blown up  :-+

   Yes, it's written in the manual, also (probably) written in the manual is that you should not measure Voltage when the probes are inserted into the Amps jacks. But despite that, a good meter should have proper input protection and save the user's ass if he mistakenly does that.
   The two Hz positions are obviously a cause of confusion, even if you have read the manual. For instance if you have multiple meters and are used to measuring frequency "the-bad-UNIT-way", on the separate Hz position.

   I think the manufacturer should put a "max 30V " next to the Hz position on the meter's front panel.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on November 23, 2012, 11:43:02 am
It will damage components if you leave it connected to that high a voltage for long. Check the schematic. Far as I'm aware, that will break either the capacitors or the chip itself in pretty short order.
Can you guesstimate what that 'short order' would be? Few seconds? Minutes? More?

Mine is working fine. It was connected for maybe one second, it started to buzzing immediately after connecting and I disconnected it immediately. On the warranty card there is a date 18 jul 2012. I bought in on taobao and the manual is only in chinese.

Thanks for the videos mariush I watched them all :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on November 23, 2012, 02:48:29 pm
It will damage components if you leave it connected to that high a voltage for long. Check the schematic. Far as I'm aware, that will break either the capacitors or the chip itself in pretty short order.
Can you guesstimate what that 'short order' would be? Few seconds? Minutes? More?

Low tens of seconds.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: rr100 on November 23, 2012, 04:02:12 pm
   I think the manufacturer should put a "max 30V " next to the Hz position on the meter's front panel.

That CERTAINLY should be the case, especially if it says 300V or 1000V beside the probe connectors.
In fact I strongly suspect this is the Voltcraft (VC) 820 (UT 60A clone) I mentioned in another thread is acting funny, I did measure Hz on mains. And YES, I did check the manual and it says 1000V on Hz.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on November 23, 2012, 04:17:17 pm
Be aware that the UT61E has a different version available in Europe. It did not pass the labelled CATIV/600V CATIII/1000V ratings. The revised version is now rated at CATII/600V and CATIII/300V and has upgraded fuses and more input protection.

So regardless of what the manual says for the non-GS approved model, it is not safe for 1000V in any way. Without the modifications that are in the GS approved model, who really knows what the safe rating for the "standard" model is as it must be worse than CATII/600V and CATIII/300V.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: M. András on November 23, 2012, 10:12:08 pm
not any higher then the battery inside the meter? :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on November 23, 2012, 10:55:06 pm
So regardless of what the manual says for the non-GS approved model, it is not safe for 1000V in any way. Without the modifications that are in the GS approved model, who really knows what the safe rating for the "standard" model is as it must be worse than CATII/600V and CATIII/300V.

There's no way you'd know it's WORSE, you're not an expert and you shouldn't make any assumptions.

Maybe it only did well at up to 800v or something like that, so they had to bring it down to whatever "level" is below 800v, which happens to be CAT II / 600v.
Maybe the meter could only handle 5000v transient voltage, less than the 6000v needed for CATIII 600v, so they had to list it as CAT III 300v which only demands 4000v transient test voltage.

Either way, you guys are blowing this out of proportion. It's a f**king 55$ multimeter, nobody's gonna climb the pole outside his house to measure the transformer, 99.5% or more will probably use it at best to measure switching power supplies voltages (400v or thereabouts).

Same with the fuse talk ... complaining it's a 250v rated fuse... duh, that's what it says on the front, current measurements 250v max.

It's really annoying... Take for example Extech ex330, the winner of Dave's 50$ meter shootout :

EEVblog #91 - $50 Multimeter Shootout - Extech EX330, Amprobe AM220, Elenco, Vichy VC99, GS Pro-50 (https://www.youtube.com/watch?v=ZoeUgMFLyAw#ws)

Yeah, I'm sure it's Cat III - 600V  and CAT II - 1000V ... with cheapo glass fuses (and ALSO 250v rated maximum, while it says 600v on the front), less internal protections... But no, let's all piss on the Uni-T meter because it's not Fluke or some other brand name.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on November 23, 2012, 11:12:26 pm
Be aware that the UT61E has a different version available in Europe. It did not pass the labelled CATIV/600V CATIII/1000V ratings. The revised version is now rated at CATII/600V and CATIII/300V and has upgraded fuses and more input protection.

So regardless of what the manual says for the non-GS approved model, it is not safe for 1000V in any way. Without the modifications that are in the GS approved model, who really knows what the safe rating for the "standard" model is as it must be worse than CATII/600V and CATIII/300V.

I'm in hart of Europe, Bosnia and Herzegovina and it is impossible to buy this meter anywhere here. I had to buy it on the internet, taobao is the cheapest.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on November 23, 2012, 11:25:15 pm
There's no way you'd know it's WORSE, you're not an expert and you shouldn't make any assumptions.

The GS approved revision has better fuses and improved input protection to make it meet CATII/600V and CATIII/300V. Therefore it is easy to deduce that the original model did not meet CATII/600V and CATIII/300V without these modifications, never mind the CATIII/1000V and CATIV/600V rating it claims to have. It is merely a logical deduction from the facts. No one needs to be an expert in anything other than logic.

And this is about the safety of the human holding the meter hen that human assumes that the company is being honest about their safety ratings, it has nothing to do with the price. If Uni-T labels something as safe for a purpose then it should be so. That is why I started the suspect meter thread so that people can see the problems with the claimed ratings.

I piss on all meters that lie about their safety ratings, not just the "poor" UT61E.

If you want a safe, well built and safe multimeter for $55, get an Amprobe AM220.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on November 23, 2012, 11:59:56 pm
Anyone who does that when the manual clearly states not to be used above 30V deserves to get blown up  :-+
Isn't this in direct violation of IEC61010 that states that the meter should be fine at any range/function with the max rated input voltage applied? Is it really stupid to apply 1000 V to an input labeled 'CAT III 1000V'? Any decent meter will survive the max rated voltage on the resistance ranges, so why shouldn't the same apply to the frequency counter range? We're not talking about GHz BW spectrum analyzer inputs that are hard to protect.

There's no way you'd know it's WORSE, you're not an expert and you shouldn't make any assumptions.
There's no way you'd have any knowledge about the expertise of other forum members. Please don't make assumptions.

Either way, you guys are blowing this out of proportion. It's a f**king 55$ multimeter, nobody's gonna climb the pole outside his house to measure the transformer, 99.5% or more will probably use it at best to measure switching power supplies voltages (400v or thereabouts).
Nobody would complain if it was labeled CAT I 300V/CAT II 200V. CAT IV 600 V should be suitable for industrial and power distribution circuits (up to 600 V).

Same with the fuse talk ... complaining it's a 250v rated fuse... duh, that's what it says on the front, current measurements 250v max.
Fuses are often blown when people try to measure voltage with the meter/leads in the current position. If you're not looking at the lead connection, than fine print near the sockets isn't going to help either. Products should be safe by design, not safe by fine print.

Take for example Extech ex330, the winner of Dave's 50$ meter shootout :
[...]
Yeah, I'm sure it's Cat III - 600V  and CAT II - 1000V ... with cheapo glass fuses (and ALSO 250v rated maximum, while it says 600v on the front), less internal protections... But no, let's all piss on the Uni-T meter because it's not Fluke or some other brand name.
The ex330 is rarely discussed, and so are its bad points.

If Fluke would make a meter like this, there would be a lot more complaints. Of course, based on past (and current) performance, people would be more skeptical about Uni-T safety testing than Fluke safety testing.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on November 24, 2012, 12:15:41 am
The problem for manufacturers is that the CE Cat ratings testing directives have changed, about 6 months ago.
Meters with a 1000V rating are now subjected to a 2000 volt input on the amps jacks, with blown fuses in place, to check for arcing inside the meter. (1000V before)
The fuses voltage rating  must now match the meter CAT voltage rating and must be ceramic HRC and fast blow. (new requirement)
All other meter inputs must survive high voltage transients, whose strength varies according to the CAT rating applied for.
The meter CAT rating is downgraded until it passes all the required tests.
So, the old UT61E doesn't comply with the new regulations, at least because of the 250V fuses and is unlikely to comply with the GS TUV approved CAT rating, without some PCB modifications.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on December 11, 2012, 04:52:15 pm
Does anybody know a way to tweak the mA range? I tested a 15.25mA current flow arrangement with Fluke 87V in Hi Res and Mastech 8218 agreeing, while Fluke 17B was showing 15.15mA, but the 61E ~13.5mA only! Fail for selecting JFETs IDSS to my circuits spec for instance!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on December 11, 2012, 05:03:18 pm
P.S. I used the same TL175 leads in all cases to avoid uncertainties due to cabling between meter tests in series mode.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on December 11, 2012, 05:22:17 pm
In another test with 10X the voltage source and a higher resistor load of the previous so to minimize different between meters burden voltage effect, the 87V was 10.05mA while the 61E 9.945mA by the way. While F17B at 10.03mA.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on December 11, 2012, 05:24:25 pm
In another test with 10X the voltage of the previous to minimize burden voltage effect, the 87V was 10.05mA while the 61E 9.945mA by the way.

And there you go. Burden voltage; you can't use the 61E for low-voltage mA/uA measurements.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on December 11, 2012, 05:33:10 pm
Still the 17B showing much closer while quoted 1.5% and 61E quoted 0.5% at that mA range when I used ~10V source and 1K 1% resistor.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on December 11, 2012, 06:41:28 pm
This is not a issue about accuracy more likely it's the burden voltage. Must be nuts to think it's the accuracy and the dropout voltage has always been a big problem for the UT61E
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on December 11, 2012, 06:59:43 pm
Will test at 20V source and 2K resistance against 87V and let you know. Still if going that high is necessary, then the 61E is no good for mA in many many situations due to excess burden, and its an  issue to be well pointed out.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on December 11, 2012, 07:06:46 pm
Test done. 87V 10.00mA, 61E 9.950mA, 17B 9.98mA.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alm on December 11, 2012, 07:12:49 pm
Try putting all three meters in series (connect common terminal of the first to mA terminal of the second, and so on) with the current source. Then the current through the meters should be identical (Kirchoff's current law), so burden voltage will not introduce any errors.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on December 11, 2012, 07:25:10 pm
87V still 10mA, 17B still 9.98mA, 61E improved to 9.989mA. All in series closing circuit. Burden change helps 61E by 0.039mA even at 20V and 2K source resistance (PSU and 2K dummy in series).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alexig on January 02, 2013, 11:30:35 am
Just received this multimeter and found something strange with it.

If I switch to the mA scale with no leads in and press the peak button, it gives me a reading of 0.21 for the Pmax and -0.25 for Pmin (both values start rising after a second or two). Same thing happens in the uA range, I get 1.8uA Pmax and -3.4uA Pmin.

If I measure the current going through a 10K resistor using a 3V battery, my Pmax rises to 0.46 to 0.53mA and Pmin as -0.012mA. Now if I leave it in peak mode, plug and unplug the load the readings go up again, Pmax goes up slightly but Pmin goes up to -0.43mA.

When measuring peak voltage of a 3V battery, Pmax slowly starts increasing and goes 30-60mV above the live reading, Pmin looks to be ok. When you disconnect and reconnect the battery Pmax reads 3.35V and Pmin reads -0.1V.

In mA mode, when I press peak and then it says CAL the number 0.834V shows up before going to -28V and then the real Pmax reading - sounds like the calibration is wrong, should it be 0V and then jump to -28V?

When the leads are out the mV selection seems to jump around quite a lot, when turned on it rises to 70mV and drops to -30mV and starts slowly increasing to -27mV, none of my other meters do this. If you pick it up and move it around or move your hands around it, it jumps all over the place and can sometimes go to overload.

Does this happen to anyone else?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dr_p on January 02, 2013, 02:05:24 pm
Plug in leads and short them, see the 0.000mA or 0.000V and be happy. You don't use it without the leads attached.

3V(sure?) on 10K(sure?) is 0.3mA. Add not perfect contact resistance and/or component tolerances and you're reading of 0.46mA...0.53mA is fine. Peak min is minus something(close to 0) because you started peak mode before connecting the resistor. What do you expect?

The single "wrong" thing is the "CAL" event, but that stinks too - the meter shows Volts readings, and you want to measure mA. Judging from your other problems, are you sure you know how to use the meter? Like plug the leads in the correct sockets?

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alexig on January 02, 2013, 02:54:56 pm
Yes when the leads are shorted it does read 0mA or 0V, it's I thought the Pmax/Pmin would work differently. Pmin I'm not too worried about but Pmax is odd to me.

I can confirm the battery voltage is 2.966V and 10K resistor reads 9.849K. The odd thing is that when I have the live reading it's 0.295mA which is all good but then I press peak, it says CAL and then Pmax goes to 0.4mA and then to 0.5mA,

Maybe I'm missing something about the physics of electronics but shouldn't the current constantly stay very close to 0.295mA and not fluctuate if I'm touching anything in the circuit? I would have expected Pmax to be a few mV higher than the live reading.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dr_p on January 02, 2013, 04:37:39 pm
The manual  (http://www.uni-trend.com/manual2/UT61English.pdf)- pg.12 and pg.39:   "CAL" means the meter enters self-calibrating mode and should be allowed to finish (e.g. don't press any key)

You did read the manual, right? :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: alexig on January 03, 2013, 09:22:09 am
Yep I have been reading the manual, when I press peak I don't press any other key until it's finished the CAL and only press peak again when the result looks similar to the live reading (after 6 seconds). When I short the leads in the current mA mode and press peak, it gives 0.2mA as Pmax. If I do the same in the Amp mode, it gives 0.3Amps.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on January 04, 2013, 06:10:10 am
Jeez. Always read the manual next time or else  :-BROKE
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on January 14, 2013, 08:02:27 pm
So, further to my fuse upgrade, I'm likely to be placing a Farnell order sometime soon, and was thinking of whacking a couple of these in: http://uk.farnell.com/bourns/2095-80-blf/gas-discharge-tube-2p-800v-20/dp/2118242 (http://uk.farnell.com/bourns/2095-80-blf/gas-discharge-tube-2p-800v-20/dp/2118242)

Comments, alternative suggestions? (note any MOV capable of handling those discharge levels by itself is not going to physically fit).

UT61E haters need not apply.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on January 15, 2013, 06:37:09 am
Yes, that was my gripe. I couldn't find a MOV easily with decent specs and certainly i don't have a MOV "recommended" rating list for DMMs
Looks like i'm getting GDTs instead  :)
I had been considering ERZV10D112 MOVs at first but then i realized 10mm discs are pretty small ... i nearly thought 10mm was huge
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on January 31, 2013, 02:59:50 am
Ah ha Mr. iloveelectronics,

I saw on your signature lines about having some UT61E to sell at your eBay store99centHobbies.com, and rather than dealing with an unknown ebay seller, I decided to get it from you.

Having deciding to purchase, a brain-freeze moment hits...  I click the tab back to ebay and click purchase there!

Well, anyhow, I hope to receive the UT61E soon.  So, stop blogging, and get to work!  (just kidding)

Rick Law
-----------------------------------



Someone find 61E about less $60 with shipping  HK or SG post? China air mail can not taking out multimeter almoust 1.5 mounth.(((

I live in Hong Kong and can get hold of the UT 61E rather easily at a cost of around $40 including shipping from China to me. Depending on where you are, I should be able to ship one out through HK post (which is quite reliable and relatively quick comparing to China post), within your budget. I'm happy to help but obviously trust will be an issue as we are strangers to each other and merely fellow forum members. If you do want me to help let me know.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on January 31, 2013, 03:17:24 am
Ah ha Mr. iloveelectronics,

I saw on your signature lines about having some UT61E to sell at your eBay store99centHobbies.com, and rather than dealing with an unknown ebay seller, I decided to get it from you.

Having deciding to purchase, a brain-freeze moment hits...  I click the tab back to ebay and click purchase there!

Well, anyhow, I hope to receive the UT61E soon.  So, stop blogging, and get to work!  (just kidding)

Rick Law
-----------------------------------

Hi Rick,

Your multimeter has been packed and ready to be shipped out today :)

Cheers,
Franky
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on January 31, 2013, 03:38:58 am
Found this nifty gadget,

http://www.voltagestandard.com/DMMCheck.html (http://www.voltagestandard.com/DMMCheck.html)

for those who wants to caliibarate thier DMM,though not necessary for Ut61E cuz already very tuned,but because pots are their it is possible


Mr. Dimitrioptimus,

Thank you for pointing this out!  For those of us wondering if the DMM is still (or ever) accurate, this really helps.  I just ordered the UT61E.  I suppose I wont need it for a few months yet.  But 12 months mark looks like the right time to adjust for the shifts.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on January 31, 2013, 04:21:19 am
To clean the terminals with cotton bar with detergent, as dirt or moisture in the terminals can affect readings
Not exactly english but they tried their best to translate, i've seen worst manuals from some "top" companies on their low-end products which are clearly some rebadged stuff (Or re-fried sick if you prefer)
Interpreted as : Clean the terminals with a cotton bar with some detergent periodically as dirt or moisture buildup can affect readings ... though i don't agree with the detergent part.

I would guess "cotton bar" is "cotton swabs" or more commonly call "Q-tips" in the USA.  I am not sure they use "detergent" to mean "cleaning agent" or really the soap-based detergent we use for dishes.  But soap based detergent is certainly a possibility.

I have actually cleaned the inside of a smart phone using dish-detergent after I dropped it in sea-water while at the beach.  I rinsed it in clean (tap) water immediately after I picked it up from the 1-2 foot deep sea-water.  It was dripping sea water as I walked back to the hotel.  I packed it wet after a good tap-water rinse at the hotel's "foot rinse" (they don't want sand in the hotel).  I kept it wet until I got home the next day.  At home, I can clean it properly.  After disassembling the phone exposing the motherboard (and daughter board which the radio is on) I washed everything with tap water and detergent again.  I then rinsed it in alcohol, dried it by my air-conditioning vent (till I think it is visibly dried plus another day and half).  Reassembled them and go.  The smart phone (Treo 650) is still in use.  I just love that darn phone and don't want to switch.

I also detergent washed some PC components.  My home server (an IBM eServer from eBay) had a fan board that failed (with much gook and gunk almost like black-jelly on it that I don't even want to touch).  I washed the board in dish-detergent (water rinse then alcohol rinsed/wiped).  I did that a few months ago and brought that fan board back to life.  The darn thing is still working with the board driving the fans properly.

So, may be they do mean regular washing detergent - perhaps not enough to be dripping but just enough to moisten the tip of the cotton swab.  Perhaps then a round of water-moisten swabbing to take out the detergent, then final a swabbing with alcohol.  That would be my guess.

If you try that, it would be at your own risk.  I certainly feel comfortable doing that.  My smart phone bath was the first "forced" experiment having dropped it into the sea - I was uncomfortable, but I know that was how a wet camera got fixed, so I just tried.  When I washed my server, I knew what I was doing then and was more confident doing it.  I certainly would be comfortable wiping connection joints, jacks, sockets, etc. with detergent then water then final wipe with alcohol.

Rick Law
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on January 31, 2013, 12:39:00 pm
(http://i.ebayimg.com/t/Limit-Digital-Multimeter-with-Large-Display-610-153220108-/00/s/NjM2WDMxMg==/$(KGrHqF,!hMFBcIHE9!rBQmn,b0O(Q~~60_12.JPG)

Check this UT61D in disguise. Doesn't that price make your eyes water...  :bullshit:
http://www.ebay.com/itm/Limit-Digital-Multimeter-Large-Display-610-153220108-/290808931137?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D5261942134715042385%26pid%3D100015%26prg%3D1006%26rk%3D1%26sd%3D290808931137%26 (http://www.ebay.com/itm/Limit-Digital-Multimeter-Large-Display-610-153220108-/290808931137?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D5261942134715042385%26pid%3D100015%26prg%3D1006%26rk%3D1%26sd%3D290808931137%26)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Teneyes on February 03, 2013, 07:53:07 am
Thanks Franky ,   
  Received in Canada 11 days after shipping, as expected, 4 days to Vancouver plus another 7 days  to Me.
 I ordered another one today as gift for my older brother, who is using analog Meter :bullshit: 5000ohms/v
This Brother got me started with a Heathkit (EK1)  Christmas gift, when I was 10 years old
Yeah  I'm old now
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on February 11, 2013, 05:47:44 pm
Hi Rick,

Your multimeter has been packed and ready to be shipped out today :)

Cheers,
Franky

Forgive me, guys, I have to blow some steam here.  Franky shipped the package same or next day (scanned/acceptance by HK post next day), that was very quick.  (Thanks Franky)

The package got to San Francisco on February 5th. 5am.   I thought, gee, I get mail from San Francisco in a couple of days.  So I have been checking, and checking, and checking, hoping to get to play with it over the weekend...   That was not to be.  I check again this morning, and the package just left San Francisco this morning, February 11th, 0:00am.  5 days and 19 hours it stayed in San Francisco to get on a truck heading East.  I hope it doesn't stop in Ohio or something before it hit the East Coast where I am.  Life is not that long; I want to get my hand on my new toy before I am stone cold and mummified...

Well, perhaps it was US Customs.  Let see if I get a US custom sticker on it (they did that once after they opened the package for inspection and re-close it with a US Customer sticker)...

I must say, most of the stuff I ordered from HK/China got here pretty quick.  About 1 in 10 takes forever.  Geez, I was really hoping to get my hands on it over the weekend of LAST week.

Rick

By-the-way, Franky, "Kung Hai Fat Choi".  In fact, "Kung Hai Fat Choi" to everyone - that is "Happy Chinese New Year" to everyone & best to all of you and your family...  Chinese New Year was yesterday.  The Chinese will be saying "Kung Hai Fat Choi" to everyone for the next week or so.  Franky is probably away gone somewhere to "Fat Choi" right now. 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 11, 2013, 05:59:25 pm
Nah, it's still chinese new year ... for china at least it's 10 whole days
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Eliminateur on February 13, 2013, 06:28:18 pm
Hmm i have a question/gripe about the UT61e:
one of the first tests i made was AC line voltage, which showed 232V (which is the correct RMS value of line voltage) then i used the peak funciton, hoping to record line variations, to my surprise it showed 328VAC as peak high...
so wwwait, shouldn't peak AC retain RMS value?, not absolute peak?, kind of confusing when used with AC.... would've much preferred the peak RMS value (which is the readout i'm getting normally)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on February 13, 2013, 06:39:41 pm
'Peak Hold' has a fast update rate to capture top and bottom of sine wave. So, the 61E meter behaves quite normally on that setting.
Max/Min selection, with a slower capture speed, would show RMS fluctuations, but the 61E meter doesn't have that feature.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Eliminateur on February 13, 2013, 06:43:41 pm
i see...
it's just a matter of "wording" then, peak is doing literally that when i was expecting a min/max

oh well i can live with that it's not a feature i'm going to using much in AC (i'll use it on DC).

BTW, i there a way to indirectly measure temperature on the UT61E with the adapter connected?, maybe in the mA range and some conversion table?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on February 13, 2013, 07:12:42 pm
I'm not sure which adapter you're talking about.
A thermocouple wil give you a voltage based on absolute temperature. You still need ambient temp measurement at the base for a meaningful temperature indication.
Dave just did a video on the subject. Go look it up.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 13, 2013, 07:21:15 pm
so wwwait, shouldn't peak AC retain RMS value?, not absolute peak?, kind of confusing when used with AC.... would've much preferred the peak RMS value (which is the readout i'm getting normally)
PEAK is basically what it is, the peak value of the wave not a min/max kind of thing
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on February 14, 2013, 06:50:39 pm
Hi Rick,

Your multimeter has been packed and ready to be shipped out today :)

Cheers,
Franky

Thanks Franky -  I got it yesterday, checked it out last night.  Works well!

I knew you shipped very quickly - according to post office tracking they got the package in tracking the next day.  Unusually this package 5 days 19 hour vacation in San Francisco before it headed east.  That was unusual.  No sign of US customs handling it, so I wonder what it did in San Francisco that long.

By the way, thanks to you folks here on this blog (and thanks, Mr. MJ Lorton.  Your YouTube reviews led me to this DMM).  I know exactly what to expect, and I know how this will serve me and where it will fail me so I made my choice with confidence.   Thanks, guys!  You folks have been most informative and the information you shared have been helpful.

So far, my only disappointment is my old USB-RS232 adapter doesn't work.  The UT61E and software are fine since they work with my old PC with a real RS232 port.  Ironically, I get this DMM to track this old PC's power supply which I suspect is failing...  Well, I guess a new USB-RS232 dongle is now on my agenda.

Rick
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: notsob on February 14, 2013, 08:20:35 pm
There is a USB adaptor option for the UT61E instead of the supplied RS232 one - ask Franky.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on February 14, 2013, 09:37:44 pm
If Franky can't get it, get it here:
http://dx.com/p/utd04-usb-data-cable-for-digital-multimeter-ut71-ut61-series-black-136cm-150054 (http://dx.com/p/utd04-usb-data-cable-for-digital-multimeter-ut71-ut61-series-black-136cm-150054)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on February 15, 2013, 12:24:48 pm
If Franky can't get it, get it here:
http://dx.com/p/utd04-usb-data-cable-for-digital-multimeter-ut71-ut61-series-black-136cm-150054 (http://dx.com/p/utd04-usb-data-cable-for-digital-multimeter-ut71-ut61-series-black-136cm-150054)

I can get those. But I won't be able to compete with them on price...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 15, 2013, 02:14:50 pm
If Franky can't get it, get it here:
http://dx.com/p/utd04-usb-data-cable-for-digital-multimeter-ut71-ut61-series-black-136cm-150054 (http://dx.com/p/utd04-usb-data-cable-for-digital-multimeter-ut71-ut61-series-black-136cm-150054)

I can get those. But I won't be able to compete with them on price...

But unlike DX, you can get it delivered the same year. ;)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on February 15, 2013, 04:15:22 pm
It takes 10 days from Frankie to me, a very fast service. He posted the next day after ordering, and I could see the HKPO held the parcels until they had a full consignment ( or the last day before New Year when they sent all regardless) and from there it was 8 days. Can't say anything wrong about the packaging, or the very nice stamps. Scary thing is the price of the postage from HK to ZA. From here to there is 3 times the amount, 6 times if you want airfreight.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on February 15, 2013, 04:23:06 pm
But unlike DX, you can get it delivered the same year. ;)

Thanks. That put a smile on my face :)

It takes 10 days from Frankie to me, a very fast service. He posted the next day after ordering, and I could see the HKPO held the parcels until they had a full consignment ( or the last day before New Year when they sent all regardless) and from there it was 8 days. Can't say anything wrong about the packaging, or the very nice stamps. Scary thing is the price of the postage from HK to ZA. From here to there is 3 times the amount, 6 times if you want airfreight.

Thanks for the kind words, Sean. You got really lucky with the stamps! They gave me the Year of the Snake special edition stamps for your package. These were only just released a few days prior to that and people were lining up to buy them! That was the only time I actually got my hands on them (literally), I couldn't believe they actually put that golden (metal?) bit on a paper stamp!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on February 15, 2013, 04:36:20 pm
Gosh...I just looked up the Hong Kong Post website and those stamps are listed here: http://www.hongkongpoststamps.hk/eng/stamps/stamps_issuing_programme/2013/index.htm (http://www.hongkongpoststamps.hk/eng/stamps/stamps_issuing_programme/2013/index.htm)

What Sean got were the ones listed under "1a". Those stamps have real gold and silver on them! I should have kept them for myself..LOL!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on February 15, 2013, 06:20:47 pm
I can post them back to you Frankie........ slightly used though. Very nice looking stamps there. It is the 1a set.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: NevDickens on February 16, 2013, 03:36:27 am
Hello Gents,
First post so please be gentle.  I purchased a UT61E a while back (thanks Franky). My new computer does not have a serial port, only usb’s.  |O    Ok need a serial to usb adapter. While checking on Ebay I found this - http://www.ebay.com.au/itm/UNI-T-Multimeter-USB-Data-interface-cable-UT-D08-replace-UT-D04-for-Windows-7-XP-/130743143940?pt=AU_B_I_Electrical_Test_Equipment&hash=item1e70e60e04 (http://www.ebay.com.au/itm/UNI-T-Multimeter-USB-Data-interface-cable-UT-D08-replace-UT-D04-for-Windows-7-XP-/130743143940?pt=AU_B_I_Electrical_Test_Equipment&hash=item1e70e60e04) . You beauty, won’t have to mess around joining up leads to adapters. The unit is the same as a Silicon Labs CP2104 USB to UART Bridge controller and as such you will also need : Leadtek_GPS_Driver.zip  so your computer will recognise the lead hook-up. And yes I know it’s a gps driver, but it works. Apparently some GPS units use the same technology.
Hope this info helps someone.
Downloaded software from site below  ;D
Cheers Neville











Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: notsob on February 16, 2013, 03:58:45 am
My last order from DX took 68 days to arrive (I had opened a missing goods ticket), my order from Franky took 8 days. The package from DX had some damage, luckily the included CD was OK but was scratched in shipment, Franky's packaging was exceptionally good, nothing was damaged or likely to be damaged.

Thank you Franky - Great service, and notification of order progress and shipping all the way.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 16, 2013, 05:27:01 am
My new computer does not have a serial port, only usb’s.  |O   
What's wrong with RS232? And plus UltraDMM is written for RS232 on the UT61E, all you need to do is connect a simple USB > RS232, that's what i do and it works
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on February 16, 2013, 05:54:42 am
My new computer does not have a serial port, only usb’s.  |O   
What's wrong with RS232? And plus UltraDMM is written for RS232 on the UT61E, all you need to do is connect a simple USB > RS232, that's what i do and it works

Not all usb/rs232 converters work with the 61E. I have tried a few different ones. The cheapest ones usually won't work.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: NevDickens on February 16, 2013, 06:19:19 am
My new computer does not have a serial port, only usb’s.  |O   
What's wrong with RS232? And plus UltraDMM is written for RS232 on the UT61E, all you need to do is connect a simple USB > RS232, that's what i do and it works

Nowhere in my post did I say that there was anything wrong with RS232! And as Franky said, not all of the RS232 to usb connections work with the 61e, so I purchased a lead that WORKS for me.
 I'm glad that the RS232 works for you.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on February 16, 2013, 06:42:03 am
UNI-T sells an RS232/USB adapter: UT-D03
http://www.uni-trend.com.cn/cp-show.asp?yy=??&ProductNO=387 (http://www.uni-trend.com.cn/cp-show.asp?yy=??&ProductNO=387)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on February 16, 2013, 06:56:29 am
I'm using a 3$ serial to usb adapter and it works just fine.

Bought it from a seller safekom from ebay, and this one he sells will probably work with the ut61e :

http://www.ebay.com/itm/USB-2-0-Male-RS232-Serial-DB9-9-Pin-Adapter-Cable-PC-/310227587778?pt=UK_Computing_Parallel_Serial_PS_2&hash=item483b0152c2 (http://www.ebay.com/itm/USB-2-0-Male-RS232-Serial-DB9-9-Pin-Adapter-Cable-PC-/310227587778?pt=UK_Computing_Parallel_Serial_PS_2&hash=item483b0152c2)

I'm saying probably because mine is semi-transparent blue, this one is black, but other than that the description of the listing sounds the same as it was when i bought mine.

An identical one as mine is sold by the same seller for a bit over 4$ along with a 9 to 25 adapter:

http://www.ebay.com/itm/1M-USB-2-0-Serial-GPS-DB-9-Pin-RS232-DB-25-Parallel-Adapter-Printer-Modem-/310353150670?pt=UK_Computing_Parallel_Serial_PS_2&hash=item48427d42ce (http://www.ebay.com/itm/1M-USB-2-0-Serial-GPS-DB-9-Pin-RS232-DB-25-Parallel-Adapter-Printer-Modem-/310353150670?pt=UK_Computing_Parallel_Serial_PS_2&hash=item48427d42ce)

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: NevDickens on February 16, 2013, 07:30:56 am
Okay, all I was doing was posting up an alternative to the RS232. If people want to use the RS232 then use it. If others like myself want to use something else then thats fine as well. This will teach me to put up a post to direct those to the software so they can use the alternative lead if they so chuse. What happened to being able to have your own opinion?
Obviously I am just a newbie, what would I know.
No more posts from me!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on February 16, 2013, 07:49:31 am
THe UT-04D USB cable should work on the 61E without the need for special hardware recognition software:
http://www.uni-trend.com.cn/cp-show.asp?yy=??&ProductNO=386 (http://www.uni-trend.com.cn/cp-show.asp?yy=??&ProductNO=386)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 16, 2013, 07:56:17 am
Okay, all I was doing was posting up an alternative to the RS232. If people want to use the RS232 then use it. If others like myself want to use something else then thats fine as well. This will teach me to put up a post to direct those to the software so they can use the alternative lead if they so chuse. What happened to being able to have your own opinion?
Obviously I am just a newbie, what would I know.
No more posts from me!

Don't mind the children, you learn to ignore them in time. Using the proper RS-232>USB adaptor made by Uni-T is definitely the best solution (although a better IC than the CP2104 would be nice).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: NevDickens on February 16, 2013, 08:39:47 am
Wytnucts-The lead I have as in my post says, is a UT-D08 made by UniTrend, the same company that makes the UT-D04 or UT-04D as you call it and as you know, anything thats hooked up to a computer needs software drivers of some sort, either whats already loaded on the computer, or what someone has to load onto it to get it to recognise that something is there. My computer obviously did not have the required driver so I found some, loaded it on and hay presto the 61e software works a treat and alls good. So if people choose the bloody RS232 then good on them, I wont be.

Monkeh
Thanks mate, as I said, I put the post up to give others an alternative and the link to the software to use if they wanted, thats all
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on February 16, 2013, 08:45:00 am
I'm using a 3$ serial to usb adapter and it works just fine.

Hi mariush,

The blue adapter you posted looks suspiciously similar to one that I've tried but it didn't work with the 61E on my Windows 7 system. The driver installs ok and the computer recognises the device when I plug it in but it just won't work with the 61E software. Are you using yours on Win7 or some other system?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Bored@Work on February 16, 2013, 08:51:11 am
I'm using a 3$ serial to usb adapter and it works just fine.

Hi mariush,

The blue adapter you posted looks suspiciously similar to one that I've tried but it didn't work with the 61E on my Windows 7 system. The driver installs ok and the computer recognises the device when I plug it in but it just won't work with the 61E software. Are you using yours on Win7 or some other system?

Let me guess, the software requires the serial interface being  one of COM1: to COM4: while the driver and Windows decided to give it a COM port > 4?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on February 16, 2013, 09:00:09 am
Let me guess, the software requires the serial interface being  one of COM1: to COM4: while the driver and Windows decided to give it a COM port > 4?

That was the easy part to fix, I just reassigned the COM port under Device Manager. I had to do it even with converters that worked with the 61E software. Problem with those el oh-so cheapo converters I tried was that they just wouldn't talk to the 61E software no matter which COM port I assigned them to.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 16, 2013, 09:07:50 am
Let me guess, the software requires the serial interface being  one of COM1: to COM4: while the driver and Windows decided to give it a COM port > 4?

That was the easy part to fix, I just reassigned the COM port under Device Manager. I had to do it even with converters that worked with the 61E software. Problem with those el oh-so cheapo converters I tried was that they just wouldn't talk to the 61E software no matter which COM port I assigned them to.

If they're PL2303 based you probably need an older driver (there are a lot of clones of the chip around, current drivers will fail to function with them).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 16, 2013, 02:59:27 pm
Franky, have you tried the HL340 adaptors?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on February 16, 2013, 03:04:52 pm
Franky, have you tried the HL340 adaptors?

Yes, those don't work on my Win7 PC. I've also tried some PL2303 (clone) based ones, but as Monkeh said, the driver didn't work. The only one I have the works is a FTDI based one.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 16, 2013, 03:22:29 pm
Franky, have you tried the HL340 adaptors?

Yes, those don't work on my Win7 PC. I've also tried some PL2303 (clone) based ones, but as Monkeh said, the driver didn't work. The only one I have the works is a FTDI based one.
These two look suspiciously like the one i had (Don't know when it was purchased, probably 8-9 years already?)
http://item.taobao.com/item.htm?spm=a230r.1.10.244.Wq1woL&id=627697674 (http://item.taobao.com/item.htm?spm=a230r.1.10.244.Wq1woL&id=627697674)
http://item.taobao.com/item.htm?spm=a230r.1.10.58.ymhju5&id=15450201948 (http://item.taobao.com/item.htm?spm=a230r.1.10.58.ymhju5&id=15450201948)
Maybe you can try them out? since it's cheaper (and faster) for you  :P
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on February 16, 2013, 03:36:05 pm
I'm using a 3$ serial to usb adapter and it works just fine.

Hi mariush,

The blue adapter you posted looks suspiciously similar to one that I've tried but it didn't work with the 61E on my Windows 7 system. The driver installs ok and the computer recognises the device when I plug it in but it just won't work with the 61E software. Are you using yours on Win7 or some other system?

Mine was autodetected by Windows and the Prolific drivers were installed and worked straight away.

Here's some internal pictures I made a while ago (so excuse the quality),  it's a prolific clone chip on one side and a Maxim rs232 driver on the other side.
I had to open it because I pulled on the cable and one of the usb cable wires got loose and had to resolder it, the wires are held inside only by solder and plastic case putting pressure on the cable jacket.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on February 16, 2013, 08:01:57 pm
I am not sure if it has been mentioned before but most RS232-USB converters don't actually provide RS232 signals. RS232 is ±12v logic level and most converters just provide +5 volt logic. Some RS232 devices will accept this and some won't.
Title: UT61E users may find useful
Post by: Rick Law on February 17, 2013, 01:07:30 am
I hate flipping through the manual to look for the %accuracy/specs each time I change the dial on my meter.  So, I cut and pasted the UT61E's spec for all the selections into a single-page layout.  Small prints, but I can see all the %accuracy for all the ranges on this little poster on my wall.

Thought other UT61E may find this useful.  If you like it, feel free to use it.

(Since the original manual is available for the public to download, I am rather sure this consolidating into single page would fall under the "fair-user" clause of the copyright act.  Well, I think so anyway.)
Title: Re: UT61E users may find useful
Post by: Teneyes on February 17, 2013, 03:30:39 am
Ithe UT61E's spec
Thought other UT61E may find this useful.
Thanks Rick :) :-+ :-+
Title: Re: UT61E users may find useful
Post by: dinoboy on February 17, 2013, 09:57:24 am
So, I cut and pasted the UT61E's spec for all the selections into a single-page layout.

Very helpful sheet, i am printing it out now.
Thanks for your efforts, great job!!

 :-+
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ddavidebor on February 17, 2013, 10:03:39 pm
i've 3 question about this meter, and interned had not answer it:

-how many fast is the continuity test?
-what is the max diode voltage drop it can measure?
-how mani reading per second it do?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 17, 2013, 10:06:03 pm
-how many fast is the continuity test?
Fast. VERY FAST. It's been answered on this topic
-what is the max diode voltage drop it can measure?
Just a little over 2V, won't measure my white LED which is a 2.4V (Odd eh?)
-how mani reading per second it do?
2. Most high res meters from china do 2
Title: UNI-T UT61E Multimeter teardown photos.
Post by: ddavidebor on February 17, 2013, 10:35:35 pm
Ok thanks a lot.

I will never find a meter capable to measure >3v led.... No way...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on February 17, 2013, 10:44:29 pm
The test voltage is up to about 2.8v so most leds will light up.
It's quite a good meter, for the money you can't go wrong.

PS. You can tests leds quite simple with a simple 470ohm - 1kohm resistor .. just use 3.3-5v and the resistor in series to limit the current.
Don't make your selection of a good meter on its ability to measure a led, you won't do that with your meter all day (at least i hope so)

Here's a very  detailed review:

Multimeter Review / buyers guide: Part 1 - UNI-T UT61E (https://www.youtube.com/watch?v=Bz6CYDRl1M8#ws)
Multimeter Review / buyers guide: Part 2 - UNI-T UT61E (https://www.youtube.com/watch?v=5YbbbgbJK9I#ws)
Multimeter Review / buyers guide: Part 3 - UNI-T UT61E (https://www.youtube.com/watch?v=P_h27mRCH6s#ws)
Multimeter Review / buyers guide: Part 4 - UNI-T UT61E (https://www.youtube.com/watch?v=q9n0scdsung#ws)
 
Title: UNI-T UT61E Multimeter teardown photos.
Post by: ddavidebor on February 18, 2013, 05:59:23 am
Thaks a lot!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 18, 2013, 07:26:03 pm
Ok thanks a lot.

I will never find a meter capable to measure >3v led.... No way...

So make a box which will do it! Whole minutes of work.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ddavidebor on February 18, 2013, 07:54:54 pm
i'm searching a good project jet  8)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 18, 2013, 07:59:20 pm
All you need is a 5V input voltage and a LM317 plus a few bits and bobs
Attach a current measuring point and a voltage measuring point at the very end of the terminals to negate multimeter burden voltage and there done! You can now measure LEDs accurately (i recommend 1 to 2 mA current though)
And also use another LM317 in front of the voltage LM317

(HINT: VC8145 can measure up to 3.3V and that's not a joke)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Spawn on February 18, 2013, 08:01:02 pm
i'm searching a good project jet  8)

Here you go:
http://www.instructables.com/id/Current-Regulated-LED-Tester/step2/Circuit-schematic-and-layout/ (http://www.instructables.com/id/Current-Regulated-LED-Tester/step2/Circuit-schematic-and-layout/)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: gatos on February 18, 2013, 09:51:25 pm
Hello sirs,
The forum is really great. I got a lot of info from your posts.
I bought also a UT61E from Franky (excellent seller)
Now I have a question:
I installed the software v4.01 (which came with the multimeter) and works perfectly apart from the frequency measurement display.
The multimeter measures and displays correct the frequency eg 50.0Hz, but the software displays 5.00Hz.
I think it is a matter of wrong decimal point position, is there any solution for this?

After, I tried the software v2.00 (which I downloaded from your site "www.uni-trend.com/Web%20site/DMM%20Software/UT61E_setup%20v2.00.exe")
With this version as far as the multimeter is taking a measurement (no matter what value), the software displays the following error message:
"-0.0001 is not a valid floating value" and the only option is to end the application.
I searched through the installation directory and I found that under the directory /Database, there are only UT70 related files,
eg UT70bdb.db, UT70bdb.px, UT70bdb.fam, UT70bdb.tv.
Should not be there any UT61 related files?
Is there any solution for this?

My PC runs on WinXP Pro, and has a real serial port.

Sorry for the long post

PS. I have already sent an email at UNI-T (since 11/2/2013), but I got no answer yet.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on February 18, 2013, 10:09:22 pm
See if you experience the same problem with UltraDMM : http://www.ultradmm.com/ (http://www.ultradmm.com/)

Title: UNI-T UT61E Multimeter teardown photos.
Post by: ddavidebor on February 18, 2013, 10:58:29 pm
All you need is a 5V input voltage and a LM317 plus a few bits and bobs
Attach a current measuring point and a voltage measuring point at the very end of the terminals to negate multimeter burden voltage and there done! You can now measure LEDs accurately (i recommend 1 to 2 mA current though)
And also use another LM317 in front of the voltage LM317

(HINT: VC8145 can measure up to 3.3V and that's not a joke)


I think a 10k resistor and a 9v battery will work well, thanks of all.

I think i'm goint to buy this multimeter when i sell the agilent 34401a.

Also i like uni-t 70... It cost 113$ and has 80000 counts. People say that 8000 count mode is very fast, and the buzzer too.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 19, 2013, 01:25:13 am
But it's rubbish and quite a lot more dangerous  :o
Title: UNI-T UT61E Multimeter teardown photos.
Post by: ddavidebor on February 19, 2013, 06:17:30 am
The uni-t ut-70d?

http://www.goodluckbuy.com/uni-t-ut70d-modern-digital-multi-purpose-meters-.html

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on February 19, 2013, 06:59:04 am
Instead of taking this thread off track, why not post questions about different meters in a new thread?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: gatos on February 19, 2013, 10:19:22 am
See if you experience the same problem with UltraDMM : http://www.ultradmm.com/ (http://www.ultradmm.com/)

Thanks mariush.
I tried DMM and everything is fine (http://www-user.tu-chemnitz.de/~heha/hs_freeware/UNI-T/dmm.zip (http://www-user.tu-chemnitz.de/~heha/hs_freeware/UNI-T/dmm.zip)).
I did not install UltraDMM because it needs .NET and several other prerequisites, and my laptop is really old adn I doubt if it can handle all these software.
 
I think the issue is that the manufacturer's software should not have any issues like those.
Fortunately there are third party solutions!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on February 20, 2013, 06:36:23 pm
Not all usb/rs232 converters work with the 61E. I have tried a few different ones. The cheapest ones usually won't work.

Another trouble is, you can't really choose the chip-set.  Even if I want to go for the more expensive ones, there is no telling if it is just more expensive for the same or if it is really better.  So basically it is a gamble.  I have a Belkin.  It worked with modems, PDA...   but not with the UT61E.

Anyone here with experience with the UTD04 cable?  I like to find out if it requires drivers and how well that worked out for you.

Thanks
Rick
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on February 20, 2013, 07:01:55 pm
The UTD-04 USB cable works fine with the UT61E.
One just needs to install the logging software that came on a disk supplied with the meter. There is no need for extra drivers (Win 7 machine here).
It works with the UNI-T 61E logging software (Ver 4.01). I haven't tried it with any third party logging software.
It doesn't work with the UT-71B/D logging applications, while connected to the 61E.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on February 20, 2013, 07:19:41 pm
The UTD-04 USB cable works fine with the UT61E.....It works with the UNI-T 61E logging software. I haven't tried it with any third party logging software.

Interesting.  Do you mind check to see if it creates a standard serial port of some sort in the hardware lists?

I was planning on writing something to copy RS232 port data to disk - not to complex a job.  If it doesn't create some kind of port and use proprietary interface method, for me, this would be opening another can of worm.

Thanks
Rick


Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on February 20, 2013, 08:10:30 pm
The cable creates a standard 'USB to serial' interface. I don't see any proprietary interface.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on February 20, 2013, 10:06:16 pm
The cable creates a standard 'USB to serial' interface. I don't see any proprietary interface.

Sorry, my question was poorly worded - let me try again:  When it is connected, does it create a COM port in the device manager's device list?

If it does, that means any 3rd party can write some code to read the COM port (or capture directly to file).  And a COM port would mean 3rd party stuff like Ultra-DMM should have no problem with it.

On the other hand, it may be like the Palm Pilot's USB-Serial (for Palm VII).  It doesn't create any COM port, but the Palm Desktop software knows how to talk to it.  Third party would have a much harder time trying to talk to the Palm VII.

Thanks...

Rick
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on February 20, 2013, 10:29:37 pm
No. The cable connection doesn't create a new COM port in the device manager list.
The only change I can see is the addition of a HID compliant device and USB input device in the Win7 device manager. Hope that helps.
I notice that the 61E logging program is similar to the 71B/D version, but with basic functionality only.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on February 20, 2013, 10:59:51 pm
No. The cable connection doesn't create a new COM port in the device manager list.
The only change I can see is the addition of a HID compliant device and USB input device in the Win7 device manager. Hope that helps.
I notice that the 61E logging program is similar to the 71B/D version, but with basic functionality only.

Thanks!  That is exactly what I wanted to know.  I appreciate your effort.

I too wish the 61E's logging is better.  That is why I have in mind writing a "read com port and save to file" util  to collect the data point first and worry about how I juggle it later.

That in mind, may be I should resurrect my old (pre-XP) laptop with real RS232 or better yet, look for my HP200 - that very tiny DOS machine has a real serial port (via a dongle) - that bugger is smaller than the UT-61E, runs full DOS with a PCMCIA/Compact flash card as HDD.  Well, that should be a fun project (when I do find time for it).  I miss that little HP200.  Fun little machine.

Rick
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 21, 2013, 12:06:13 am
The cable creates a standard 'USB to serial' interface. I don't see any proprietary interface.

No. The cable connection doesn't create a new COM port in the device manager list.

I'm not seeing your standard, non-proprietary interface.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on February 21, 2013, 12:23:25 am
In 'Devices and Printers'
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 21, 2013, 12:24:24 am
In 'Devices and Printers'

That's a name. Nothing more.

It's Windows. It's serial. It's not a COM port. Enough said..
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on February 21, 2013, 12:30:50 am
I never said it was a COM port.
I said there is no new COM port in the 'Device Manager' list.
Now, if you think it creates a new COM port, good for you. I'm not terribly interested anyway.  ::)
Buy the frigging cable and leave me out of your hacking efforts.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 21, 2013, 12:34:58 am
I never said it was a COM port.

Never said you did. You did however claim it was some sort of standard interface, which, seeing as it's not a COM port..

Quote
Now, if you think it creates a new COM port, good for you. I'm not terribly interested anyway.  ::)

Uh, okay, whatever.

Quote
Buy the frigging cable and leave me out of your hacking efforts.

......... Sorry, I don't even know what the hell you're saying there.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: notsob on February 21, 2013, 01:23:06 am
THE 'friggin' cable'   UNI-T UT-D04

http://www.ebay.de/itm/UNI-T-UT-D04-USB-INFRARED-INTERFACE-CABLE-UT71-UT81B-/360492337463?pt=LH_DefaultDomain_0&hash=item53ef048937 (http://www.ebay.de/itm/UNI-T-UT-D04-USB-INFRARED-INTERFACE-CABLE-UT71-UT81B-/360492337463?pt=LH_DefaultDomain_0&hash=item53ef048937)

or buy one from Franky ( massively better service )  my order was posted in HK on a Friday and was Delivered in Australia on the following Tuesday
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on February 21, 2013, 01:33:09 am
I don't understand why you don't just get one of the serial to usb adapters I linked to, or something similar. If for some reason it doesn't work with your computer, it's just 3-4$ wasted and you can get another model.

It shows up as a regular com port, the data the meter sends is well documented in the chip datasheet ... it's nothing special about it, just playing with the bits in a fixed set of character the meter sends twice a second.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 21, 2013, 01:54:24 am
THE 'friggin' cable'   UNI-T UT-D04

http://www.ebay.de/itm/UNI-T-UT-D04-USB-INFRARED-INTERFACE-CABLE-UT71-UT81B-/360492337463?pt=LH_DefaultDomain_0&hash=item53ef048937 (http://www.ebay.de/itm/UNI-T-UT-D04-USB-INFRARED-INTERFACE-CABLE-UT71-UT81B-/360492337463?pt=LH_DefaultDomain_0&hash=item53ef048937)

or buy one from Franky ( massively better service )  my order was posted in HK on a Friday and was Delivered in Australia on the following Tuesday

I know which bloody cable it is. I even have the schematic. It uses a cheap chip from a dead company. The UT-D08 is a better choice by far.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on February 21, 2013, 02:03:14 am
I don't understand why you don't just get one of the serial to usb adapters I linked to, or something similar. If for some reason it doesn't work with your computer, it's just 3-4$ wasted and you can get another model.

It shows up as a regular com port, the data the meter sends is well documented in the chip datasheet ... it's nothing special about it, just playing with the bits in a fixed set of character the meter sends twice a second.

re: why you don't just get one of the serial to usb adapters...
I actually did - it just arrived DOA.  Plus my other two existing ones I have that didn't work.  That is zip for 3.  I would be foolish to order a forth and just hope.  Thus I looked into the UT's USB cable.

- - -

re: It shows up as a regular com port, the data the meter sends is well documented in the chip datasheet ... it's nothing special about it...
Exactly.  The UT61E-RS232 works on my desk top, I can see the bytes coming in with just a few lines of code.  I just can't move my desktop around easily; but my laptops have no RS232.  Since I am not particular about plotting it, thus the thought:, argh, I will just write some C or even Basic, and run it off my old (DOS-era) laptop with real RS232, dump the data into a file, now I can convert the data to whatever form I want to plot.

- - -

Those back-and-forth just kicked up some nice memory - Remembering I have two Hp200Lx is kind of nice.   That little tiny DOS machine (with real RS232) is smaller than the UT61E itself and run on two rechargeable AA cells.  I can actually have some good data collection/plotting capability that I can move around easier than I can move my laptop.  That would be a fun little project to do.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 21, 2013, 12:10:08 pm
UltraDMMs creator has spoken up about it before on the thread, it's recognized as a HID device not a COM device
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on February 22, 2013, 05:01:56 am
UltraDMMs creator has spoken up about it before on the thread, it's recognized as a HID device not a COM device

Arrgh...

I spend so much time reading to learn about the UT61E as I was waiting for mine... I forgot what I did read...

Sorry for the repeat.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: gatos on February 22, 2013, 03:57:57 pm
See if you experience the same problem with UltraDMM : http://www.ultradmm.com/ (http://www.ultradmm.com/)
Dear maruish, I am back!
I installed .NET in my laptop (I had to find on offline installer), and I installed UltraDMM as well.
I have to say that it is really a powerful software with many capabilities and a very nice GUI. But my oldie laptop (Celeron 333MHz) was placing a lot of effort to cope with it (always above 90% CPU usage).
Anyway I tried some measurements, they were fine apart from the frequency measurement: the meter shoes 50.0 Hz and the software displays 500 mHz.

Thank you very much for your proposal (very nice software indeed)!

PS still waiting answer from Uni-Trend.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dr_p on February 22, 2013, 11:39:02 pm
I installed .NET in my laptop (I had to find on offline installer), and I installed UltraDMM as well.
I have to say that it is really a powerful software with many capabilities and a very nice GUI. But my oldie laptop (Celeron 333MHz) was placing a lot of effort to cope with it (always above 90% CPU usage).
Anyway I tried some measurements, they were fine apart from the frequency measurement: the meter shoes 50.0 Hz and the software displays 500 mHz.

Thank you very much for your proposal (very nice software indeed)!

PS still waiting answer from Uni-Trend.

UltraDMM seems to require a 2GHz CPU, so your problem is not necessarily from the meter, but maybe from the software.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: gatos on February 24, 2013, 12:37:17 pm
I know that about UltraDMM, but I wanted to honor the author of the software by testing it since he proposed it!
I am absolutely sure that my meter has no problem in the frequency measurement (triple checked with other multimeters).
The problem lies on the software (the software of Uni-Trend as well-see my previous posts).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: gatos on February 24, 2013, 01:48:31 pm
Dear sirs,

I have one question for you. I own an old Summit SDM383 (non TrueRMS), a recently bought Vichy VC99 (non TrueRMS) and a recently bought UNI-T UT61E.

I friend of mine brought a Fluke 79 III, so I took advantage to take some measurements.

           230V AC                 UPS output            12V DC                     1.5V DC           200Ohm Resistor
              (grid outlet)   (modified sinewave)   (old 23A battery)        (AA battery)           (2%)
79III          237                        235.5                      9.5                              1.469                  199.8
SDM383     234                        205                      11.08                              1.485                  193.8
VC99         237                        205                       11.02                             1.468                  200
UT61E       238.5                     236.3                    11.03                              1.468                  199.87
 

Unfortunately Fluke has not been calibrated for the last 4 years.
Do you consider wise to “calibrate” my other multimeters according to Fluke measurements?

Especially for the 23A battery, I think Fluke puts a lower resistance so it draws more current from the battery trying to show if the battery is able to deliver power. I won’t change anything here.


I am looking forward for your valuable opinions.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 24, 2013, 01:55:18 pm
It looks painfully obvious NOT to calibrate according to the Fluke especially when it doesn't have less accuracy rating than the UT61E plus it hasn't been callibrated for 4 years

It doesn't look obvious enough?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on February 24, 2013, 05:51:22 pm
Never adjust one meter to another without knowing which is correct. One of the multimeter check devices from Doug at voltagestandard.com is a worthy purchase for anyone worried about the accuracy of their measurements. They aren't very expensive and seem to be reliable.

Just because the one meter is a FLuke does not mean it is more accurate than the UNI-T.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 24, 2013, 06:31:05 pm
Especially for the 23A battery, I think Fluke puts a lower resistance so it draws more current from the battery trying to show if the battery is able to deliver power. I won’t change anything here.

Why don't you check that? Because it should be the same impedence. Which means the Fluke is badly out of spec on DC volts.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: gatos on February 24, 2013, 07:04:20 pm
At T4P: it is obvious. But don't you think that I should tweak up a little bit the Summit on AC Voltage?

At Lightages: I agree with you. I would like to get a "DMMcheck Plus" in the future.

At Monkeh: Unfortunately Fluke is away. I wouldn't say that Fluke is out of spec on DC volts (check the measurement on the 1.5V battery). Because the 12V battery (type 23A) was used, I think it had a way to tell the user that this battery is of no use anymore. Remember some old-cheap multimeters that they had a special range for measuring 1.5V and 9V batteries?
Maybe Fluke implements this kind of measurement? Just a guess!

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on February 24, 2013, 07:16:32 pm
Don't tweak anything without knowing which is wrong. No Fluke ever had a battery test function. The input impedance of multimeters is 10megohm, or more. There is no way for that fluke to load that battery to give a lower voltage. It appears to be out of spec as has already been said.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 24, 2013, 07:19:16 pm
At Monkeh: Unfortunately Fluke is away. I wouldn't say that Fluke is out of spec on DC volts (check the measurement on the 1.5V battery). Because the 12V battery (type 23A) was used, I think it had a way to tell the user that this battery is of no use anymore. Remember some old-cheap multimeters that they had a special range for measuring 1.5V and 9V batteries?
Maybe Fluke implements this kind of measurement? Just a guess!

I assure you, it does nothing of the sort. That Fluke should have 11M across it in VDC at that range. It is wildly out of spec.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ddavidebor on February 24, 2013, 08:16:48 pm
in fact, chinese meter usually have good calibration.

i've never found one out of specs when new... (something under 20$, but it's rubbish)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 25, 2013, 05:25:00 am
AC Voltage? That thing is TrueRMS! So really don't attempt it.
Best step here is get the UT61E callibrated and use it to callibrate the 79III and the others
Title: UNI-T UT61E Multimeter teardown photos.
Post by: ddavidebor on February 25, 2013, 06:05:35 am
Found a son of someone who go to electronic school and has access to 6.5 digit multimeter...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on February 25, 2013, 06:37:47 am
... and a recently bought UNI-T UT61E ... ...friend of mine brought a Fluke 79 III...Unfortunately Fluke has not been calibrated for the last 4 years... ...Do you consider wise to “calibrate” my other multimeters according to Fluke measurements?

If your UT61E is recent, and you are considering using a (calibration-wise) 4yr old Fluke 79III to calibrate your new UT61E -- that (to me at least) means you are not trusting the UT61E being within spec.  Why not get a DMM-Check (plus) from VoltageStandard.com.  Now you have reasonably good and absolutely fresh references to go by.

I did not take a count, but based on memory: I have seen (4+) folks here posted that their UT61E (as delivered) are in spec, and only one post I can recall saying the 61E being slightly off-spec on delivery.  If you decide not to go with DMM-Check, it sounds to me a good bet to just trust the 61E to be the more accurate of the bunch.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: gatos on February 25, 2013, 06:16:59 pm
At Lightages and Monkeh: I agree, but I can not explain the measurement on 1.5V battery and the difference with the 12V.
                                          Any ideas?

At T4P: Don't you think that I have to tweak up the SUMMIT, in accordance with the other three (at AC voltage-grid outlet)?

As I said before, I would like to buy a DMMcheck plus (start saving money-remember we have crisis in Greece!).

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on February 25, 2013, 06:54:53 pm
At Lightages and Monkeh: I agree, but I can not explain the measurement on 1.5V battery and the difference with the 12V.
                                          Any ideas?

Resistor network.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on February 25, 2013, 07:09:41 pm
As Monkeh said, the internal resistor network that is used to divide might be faulty. But this is getting way off topic and we are polluting this thread. Please start another thread if you want to discuss adjustment and calibration of anything other than a UT61E.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on February 26, 2013, 01:08:21 am
I don't understand what he means by "SUMMIT" and he's derailling the thread ...  >:(
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: gatos on February 26, 2013, 06:07:40 am
I don't understand what he means by "SUMMIT" and he's derailling the thread ...  >:(
Summit=brand of multimeter. See my post at  February 24, 2013, 01:48:31 PM. I think it is obvious  :-+

I'm not trying to derail the thread. Sorry for polluting the thread.

I understand after all that I should trust the newly bought UT-61E (and buy a DMMcheck).

Thank you for your opinions and I can assure you that I did not meant to upset anyone.
Have a nice day.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: erick on March 17, 2013, 08:14:55 pm
Hello, everyone.

Although this is my first post, I've been following the forum and watched Dave's videos for quite a good time. A lot of fun and useful information.

I am a mechanical engineer, and electronics for me is just a hobby. So far, all my small projects are arduino related. So, in terms of electronics, I am a complete newbie.

Well, let's go. After watching Dave's shootout video, I decided to buy a UT61X to replace my cheaper multimeter. I could not decide between UT61D and UT61E, though, and then I came to this thread.

Although I find the backlight feature in UT61D really handy, the better specs of the UT61E model would certainly catch my favour. By reading your posts, however, I disappointedly found out about the burden voltage downside.

According to Dave's video, UT61D has surprisingly low burden voltage. Here comes my question. Since the UT61E is expected to deliver better accuracy, isn't it supposed to, at least, be as good as UT61D in terms of burden voltage? Is there a technical explanation to this fact? I mean, isn't burden voltage somehow related to accuracy?

I apologize if that is too silly a question. I just want to try to understand a bit more about multimeters specs.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on March 17, 2013, 09:43:53 pm
Burden voltage is another spec that doesn't necessarily have to be low for a meter to have other specs with high accuracy. Yes it is horrible with the UT61E. For a bit more, $90, get the Amprobe AM-270 if you can it into Brazil without high taxes. I know how hard it is to get anything in South America for normal prices.....
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on March 17, 2013, 11:06:08 pm

According to Dave's video, UT61D has surprisingly low burden voltage. Here comes my question. Since the UT61E is expected to deliver better accuracy, isn't it supposed to, at least, be as good as UT61D in terms of burden voltage? Is there a technical explanation to this fact? I mean, isn't burden voltage somehow related to accuracy?

I apologize if that is too silly a question. I just want to try to understand a bit more about multimeters specs.

The "brains" inside the UT61D is totally different than the one inside the UT61E, they're made by different companies, with different features and so on. So it's no surprise the burden voltage is a bit different, the meters don't have the same components inside.

All meters have burden voltage, can't really get around that, it's just that ut61e has quite a big value (about 1v for the 220mA range)
Even Fluke meters aren't so awesome when it comes to burden voltage:

http://www.fluke.com/fluke/usen/community/fluke-news-plus/ArticleCategories/Electrical/BurdenVoltage.htm (http://www.fluke.com/fluke/usen/community/fluke-news-plus/ArticleCategories/Electrical/BurdenVoltage.htm)

Quote
In the case of the 87V which I mentioned earlier, the burden voltage for the 400 mA range is typically 1.8 mV/mA. What that means is that if we're reading 1 ma, there will be 1.8 mV drop across the terminals of the meter, and if we're reading 300 mA, there will be roughly 0.54 volts drop across the terminals.

So if you're really trying to measure some low voltage stuff, with low power consumption, even with Fluke the 0.3-0.5v drop will be an issue.

Not much you can do about it other than possibly using clamp meters or using a device like dave's uCurrent.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: erick on March 18, 2013, 01:58:54 am
Thanks for the answers, guys.

mariush,

I didn't think there was so much difference between the models, since they belong to the same series. That explains it.

Lightages,

There is no way I can get an AM-270 for $90.00 here =/

Even the Uni-T may end up costing me about $100.00 if I get caught and have to pay taxes. Anyways, I will just look for a good price on ebay or DX.com and buy a UT61E.

In what concerns low voltage measures, I'll be probably using something like Dave's product, as mariush pointed.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dr_p on March 18, 2013, 07:52:58 am
I doubt you'll find it cheaper than from Frakie:

https://www.eevblog.com/forum/buysellwanted/brand-new-uni-t-ut61e-for-sale/ (https://www.eevblog.com/forum/buysellwanted/brand-new-uni-t-ut61e-for-sale/)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: HKJ on March 18, 2013, 05:00:05 pm
The burden voltage on auto ranging DMMs, include 61E, is a bit funny.
They usual combine two ranges on each switch position, i.e. two mA ranges when the switch is on mA and two uA ranges when the switch is on uA. These two ranges has to share the same resistors. This will give a low burden voltage on the low mA range and a high burden voltage on the high mA range (same for uA).

A good way to get a low burden voltage is to use a external resistor. With the UT61E a 0.1 ohm resistor will give a very good high mA range. At 1A the burden voltage will be 0.1 volt and at lower current you will have a resolution of 0.1mA.
With a external resistor it is also possible to connect the resistor without adding long test wires that add to the burden voltage (The test wires will only carry voltage, not current).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: JimmyMz on March 22, 2013, 08:40:05 pm
What size is the ceramic capacitor on the back of the board, corresponding to the negative battery post terminal (C36)? I scorched mine, and fixed it with an electrolytic, but I want to put a SMD part back in. I don't know SMD sizes yet, so the help is definitely appreciated. Thank you  :D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on March 23, 2013, 04:56:07 am
What size is the ceramic capacitor on the back of the board, corresponding to the negative battery post terminal (C36)? I scorched mine, and fixed it with an electrolytic, but I want to put a SMD part back in. I don't know SMD sizes yet, so the help is definitely appreciated. Thank you  :D

It is a 1206 size (metric code 3216) 10uF capacitor.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: JimmyMz on March 23, 2013, 06:03:16 am
It is a 1206 size (metric code 3216) 10uF capacitor.
I knew it was 10uF. Regardless, thank you for including the package size. 1206 is what I needed, thank you :)
Title: My 61E's input mods
Post by: em132 on April 03, 2013, 10:25:40 am
Parts used:

1x SIBA 10A, 1,000V, 30kA, 5AG (eBay)
1x SIBA 0.5A, 1,000V, 3AG (eBay)
2x Littelfuse CG21000L GDT's (Digi-Key)
4x Littelfuse 1/4" fuse clips (Digi-Key)

Cost: ~$27 USD (not incl. S&H)

As others have surmised in this thread, GDT's are perhaps the only way to go for the clamping devices... that is, if you want to maintain the meter's 1,000V measuring ability. The ideal MOV's in this case would've been the V10D112 (or equivalent), but they are simply too fat and tall to fit, and you just can't bend them over either because the battery compartment is in the way. (BTW, the V10D112's are the same "monsters" used in the BK2709--the ones that had Dave gushing in his $100 shootout.) The CG21000L's I used are downright tiny in comparison, but they cost ~3.5x more than the V10D112's. Also, while GDT's do have a slower response time than MOV's, they aren't as prone to "blowing up" and they don't add nearly as much capacitance to the input circuit (i.e. the residual capacitance on my 61E went from 56pF to 60 after the mod).

It's a similar story with standard 5AG fuse clips; at ~18-19mm tall they're just too damn big to fit in the 61's. To put a 5AG fuse in the 10A spot you pretty much have no choice but to use a 3AG (1/4") clip and stretch it out (it can be done, and the results work surprisingly well, provided you do it carefully, without rushing). Another thing, the PCB holes in the mA fuse (F1) area will only support a 3AG fuse, not 5AG. Finally, if for whatever reason you want to fit a 3AG in the 10A spot instead of a 5AG, you'll need to drill an extra hole near the PCB mounting screw hole to ensure proper distance between the two clips--either that or only use one solder lug on one of the fuse clips (NOT recommended).

Anyway, here are the pics:

(http://imageshack.us/scaled/thumb/404/emut61e01.jpg) (http://imageshack.us/a/img404/9410/emut61e01.jpg) (http://imageshack.us/scaled/thumb/443/emut61e02.jpg) (http://imageshack.us/a/img443/6356/emut61e02.jpg) (http://imageshack.us/scaled/thumb/577/emut61e03.jpg) (http://imageshack.us/a/img577/5599/emut61e03.jpg)

NOTES: Wrapped the PTC's in heatshrink, because that's the way it's done in most hi-end meters (monkey see, monkey do!). I also wrapped the GTD's in clear vinyl tubing and added some 0.5mm-thick flame-resistant insulating sheet (taken from an old PC monitor) around the fuses for increased spark-over resistance. :-/O


More pics...

(http://imageshack.us/scaled/thumb/96/emut61e04.jpg) (http://imageshack.us/a/img96/3470/emut61e04.jpg)
Because my abode is a 100% alkaline-free zone!


(http://imageshack.us/scaled/thumb/15/emut61e05.jpg) (http://imageshack.us/a/img15/56/emut61e05.jpg)
Test lead kit family portrait:

UNI-T UT-C07 multi-purpose probe clips (DX)
UNI-T UT-C04 large alligator clips (NY Platform)
Mini alligator clips (Franky Tong <--  :-+ )
UNI-T UT-C08 probes (GoodLuckBuy)
Stackable short leads (DIY using parts from DX, Performance-PCs & Franky)
E-Z-Hook minigrabbers (Digi-Key)
Hook Clips (Franky)
2x pairs female banana plugs (Franky)
UNI-T UT-L14 silicone test leads (NY Platform)
UNI-T UT-D04 USB cable (409shop)


(http://imageshack.us/scaled/thumb/839/emut61e06.jpg) (http://imageshack.us/a/img839/6782/emut61e06.jpg)
Packed to the hilt! NOTE: The case (and the USB cable) are from a UT71A I bought from 409shop over a year ago. After comparing it to another (older) 61E I couldn't get rid of it fast enough. Of course, I kept the cable and that really nice carrying case for myself.  >:D


(http://imageshack.us/scaled/thumb/577/emut61e07.jpg) (http://imageshack.us/a/img577/5638/emut61e07.jpg)
The end.  8)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on April 03, 2013, 11:07:19 am
Nice job. Possibly not much of an improvement, because of trace spacing and general construction, but it looks good. Check the accuracy of the 10 amp range now, as the fuse is part of the shunt and any change in resistance will affect the original calibration. It is less of a problem on the mA side.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on April 03, 2013, 11:11:25 am
Nice job. Possibly not much of an improvement, because of trace spacing and construction, but it looks good. Check the accuracy of the 10 amp range now, as the fuse is part of the shunt and any change in resistance will affect the original calibration.

You want to double check that?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: c4757p on April 03, 2013, 11:15:04 am
Check the accuracy of the 10 amp range now, as the fuse is part of the shunt and any change in resistance will affect the original calibration.

Wait, really? How idiotic!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on April 03, 2013, 11:15:19 am
Check the accuracy of the 10 amp range now, as the fuse is part of the shunt and any change in resistance will affect the original calibration.

Wait, really? How idiotic!

No, not really.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on April 03, 2013, 11:34:06 am
I checked the UT71 circuit and it does look like the measurement is also done on the shunt only. Mine went out of calibration after the fuse mod, for other reasons, obviously. Thanks Monkeh, learning everyday ;)
No harm in checking calibration anyway... ))
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: em132 on April 04, 2013, 09:20:18 am
Nice job.

Thank you.

Possibly not much of an improvement

Maybe... Maybe not.

With respect, is it any worse than your 71B? How many spark-gaps has yours got?

because of trace spacing and general construction

Again, with respect, has it been determined with absolute certainty that "trace spacing" was the main factor in downgrading the "GS" models to Cat III 300V / Cat II 600V, and not, perhaps, just it being another simple case of legal "cover-your-ass-itis?"

As for the "general construction," you'd be hard-pressed to find a better solution for isolating the battery (esp. compared with the 71 series!). The 10A fuse is also essentially isolated in its own little corner of the board. The thick plastic input jack "buckets" each act as circular isolation slots, and (to my eyes) the blast protection around the case seems to be well implemented (deep U-groove and thick sidewalls).

Am I missing something?

Not looking to start anything (really!), but a little perspective would be nice.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on April 04, 2013, 11:42:22 am
I have known Wytnucls the man famous for defending his dear UT71X series DMMs

While his comes with glass fuses ours come with ceramic fuses stock  :) That just shows how much this DMM has to give in terms of safety (If not for cost cutting by UNi-T's beancounters)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: M0BSW on April 04, 2013, 06:04:18 pm
 I got mine today and I really like it for my low powered  radio amateur projects and radio servicing , I'm really interested in the backlight hack, must loo it up.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on April 04, 2013, 06:41:02 pm
Nice job.

Thank you.

Possibly not much of an improvement

Maybe... Maybe not.

With respect, is it any worse than your 71B? How many spark-gaps has yours got?

because of trace spacing and general construction

Again, with respect, has it been determined with absolute certainty that "trace spacing" was the main factor in downgrading the "GS" models to Cat III 300V / Cat II 600V, and not, perhaps, just it being another simple case of legal "cover-your-ass-itis?"

As for the "general construction," you'd be hard-pressed to find a better solution for isolating the battery (esp. compared with the 71 series!). The 10A fuse is also essentially isolated in its own little corner of the board. The thick plastic input jack "buckets" each act as circular isolation slots, and (to my eyes) the blast protection around the case seems to be well implemented (deep U-groove and thick sidewalls).

Am I missing something?

Not looking to start anything (really!), but a little perspective would be nice.
I have a 61E too. Good machine in its price range.
I don't think the 71B I modified offers better protection than yours. It was just a fun thing to do. The only way to tell would be to put them through some high voltage testing, like what the IEC61010 regulations require. For what it's worth, the original 61E didn't survive 2500V on the volt jack, as per Lightages' recent test. The 71 did.
The GS approved UT-61 is a different animal. The few pictures I saw, showed a PCB that was completely reworked to meet specifications.
I use my meters on the bench for low voltage stuff and that's where the 71 excels. I wouldn't recommend it for anything else. If I had to tamper with appliances connected to the mains on a regular basis, I would buy a Fluke for peace of mind.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: em132 on April 06, 2013, 01:29:33 pm
The only way to tell would be to put them through some high voltage testing, like what the IEC61010 regulations require

Anyone check to see if these new regs require the whole meter to be CAT rated to its lowest common denominator? By that I mean, all (?) the Fluke/Amprobe/etc. meters I've seen don't have any voltage rating printed on the current jacks, only the V-ohms (or a single rating which visibly applies to all the jacks). It's assumed the CAT/voltage rating applies to all jacks equally (rightfully so in the case of Fluke, which all have 1,000V HRC fuses, AFAIK). That's not the case with the "regular" (non-GS) UNI-T's, where the amps voltage rating is stated as significantly lower (250VMAX) than the meter's CAT rating (on the V-Ohm jack), because of the low-voltage fuses used. If these new regs require meters to be max-rated no higher than the fuse voltage, then I can see why the GS UNI-T's had their CAT rating down-rated, even if the voltage input may still technically pass CAT III/1,000V.

For what it's worth, the original 61E didn't survive 2500V on the volt jack, as per Lightages' recent test. The 71 did.

Lightages also said "CAT tests do not require that the meter continue to work after the test."

Hi-voltage surges can be unpredictable beasts. You could do 5 of these kinds of tests and end up with different outcomes in each one (from a "still working or not" point of view).

In the end though, if none of them blow up or catch fire, then they pass.

The few pictures I saw, showed a PCB that was completely reworked to meet specifications.

Very likely because those pics you saw were of either the "C" or "D" model.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on April 06, 2013, 03:24:16 pm
From my interpretation, yes any meter must meet the same CAT rating on all terminals at all settings. The meter cannot have different CAT ratings for different terminals. This is from the most recent CAT requirements but earlier versions allowed it appears. To me, the latest rules make sense because the rules are there for safety when things go wrong. You cannot pick and choose what type of "wrong" happens.

The images that Wytnucls was referring to are from the forums at mjlorton's site:
http://mjlorton.com/forum/index.php?topic=140.msg1052#msg1052 (http://mjlorton.com/forum/index.php?topic=140.msg1052#msg1052)

And yes they modified the protection and it still had to be down rated. So I can only assume that the non GS version doesn't even meet the GS specs. Who knows what the real CAT rating of the UT61E normal version is? In this case it is best to keep it for use below 250V and probably no more than CATII.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on April 06, 2013, 03:43:15 pm
They did nothing but fit a GDT and put HRC fuses in. There are no other changes to that meter.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: em132 on April 06, 2013, 03:51:46 pm
From my interpretation, yes any meter must meet the same CAT rating on all terminals at all settings

Okay, so that explains why you won't see separate voltage ratings on Fluke's Amp/mAmp/µAmp jacks (unlike the UNI-T's).

But my question still stands: if under the "GS guidelines" the CAT rating must apply to all terminals, then why assume that the 61E's "down-rating" is due to it failing the CAT III/1000V test on the V-Ohm side when in fact it could simply be due to the fuses being rated at only 600V (or 690V as the case may be)?

And unless I'm missing something, Torrentula's 61E has the exact same trace layout as the non-GS version.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on April 06, 2013, 04:39:59 pm
It could have failed either tests or both for the CAT III 1000V rating. (Destructive pulsed 8000V arcing on the volt/ohm ranges and/or 2000V arcing on the amp ranges).
In the end, UNI-T chose to apply for a CAT II 600V CAT III 300V listing, with pulsed 4000V and 1200V testing with the required 600V HRC fuses.
And yes, the first GS 61 I saw was probably a C/D model with a different layout.
On the GS61E, the bottom part of the PCB I looked at recently, is similar to the older version, except perhaps for beefier PTCs. I don't know if the traces have the same copper thickness.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on April 06, 2013, 06:28:51 pm
But my question still stands: if under the "GS guidelines" the CAT rating must apply to all terminals, then why assume that the 61E's "down-rating" is due to it failing the CAT III/1000V test on the V-Ohm side when in fact it could simply be due to the fuses being rated at only 600V (or 690V as the case may be)?

They added bigger PTCs, a spark gap that wasn't there before, 600V rated fuses, and it still was rated lower than the original. The original model has only 250V rated fuses and poorer input protection so it cannot be rated at 600V, only 250V. The CATII is a safety margin over what the GS is rated because the original has less input protection. Simple logic.

But the main thing is to realize that the UT61E's original safety ratings are an outright lie and should not be trusted. We can only guess what its true CAT rating is.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on April 06, 2013, 11:24:42 pm
The original PTC is a MWZ11 75HV made by Sinochip. I couldn't find the exact reference, but I think it has a resistance of 1.1K Ohm, a withstanding voltage of about 900V, max current of 300 mA and a switching temperature of 75c.
http://www.sinochip.net/eng/wmz11a.pdf (http://www.sinochip.net/eng/wmz11a.pdf)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: metRo_ on April 15, 2013, 06:38:22 pm
There are any cheap case for this DMM that I can buy at ebay? Thanks :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ACvolts on April 17, 2013, 01:17:11 am
The input protection circuitry looks a bit whimpy but other than that the build quality looks excellent. I like how they didn't use just one of those ICs covered in a blob of plastic. The red board is also a special touch (getting quite tired of all the green ones).

It looks like you've got a really decent meter.

Dude!.. ahhhh, I think that's orange, not red.  :P  :-DMM
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on April 17, 2013, 01:27:06 am
The input protection circuitry looks a bit whimpy but other than that the build quality looks excellent. I like how they didn't use just one of those ICs covered in a blob of plastic. The red board is also a special touch (getting quite tired of all the green ones).

It looks like you've got a really decent meter.

Dude!.. ahhhh, I think that's orange, not red.  :P  :-DMM

You dug up a post from 2011 to say that?

And no, it's red.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ACvolts on April 17, 2013, 01:45:16 am
Who said that is mandatory that 0.025% DMM's should be rated at least CATIII and have HRC fuses?
Maybe there is a market for less protected meters used in let's say, microcontroller bussiness for less than 5V powered boards.

I don't know about that but, your nickname is interesting, I like IpMan I and II but the 3rd
was so/so.  The original actor split, probably because he got hurt and/or not enough scratch.  %-B

I seen this thread too late and the DMM is up to $72.00 now.  :o
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on April 17, 2013, 01:50:14 am
I seen this thread too late and the DMM is up to $72.00 now.  :o

No, it's not. (http://www.ebay.com/itm/200901686717)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ACvolts on April 17, 2013, 02:20:07 am
The input protection circuitry looks a bit whimpy but other than that the build quality looks excellent. I like how they didn't use just one of those ICs covered in a blob of plastic. The red board is also a special touch (getting quite tired of all the green ones).

It looks like you've got a really decent meter.

Dude!.. ahhhh, I think that's orange, not red.  :P  :-DMM

You dug up a post from 2011 to say that?

And no, it's red.

Nope. heh, still looks like an orange but it's probably the
jpeg that did that.  I'm still reading the old messages!
 :P
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dr_p on April 17, 2013, 08:14:35 am
And no, it's red.

No, it's not. (http://www.ebay.com/itm/200901686717)

So funny :-DD  It's like people are  :scared:  and you go "ah...no".


(http://operationrainfall.com/wp-content/uploads/2012/06/Office-Space-Boss.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on April 17, 2013, 08:39:30 am

So funny :-DD  It's like people are  :scared:  and you go "ah...no".


(http://operationrainfall.com/wp-content/uploads/2012/06/Office-Space-Boss.jpg)

Well, at least he provided a link to my eBay store :)

Thanks for the plug, Monkeh!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on April 17, 2013, 03:25:43 pm
Thanks for the plug, Monkeh!

Thanks for the plugs, Franky! ;)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on April 18, 2013, 04:01:55 am
Thanks for the plug, Monkeh!

Thanks for the plugs, Franky! ;)
*cough* I see what you did there
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dr_p on April 23, 2013, 01:11:27 pm
I'm pleasantly surprised by the UT61E. Among the obvious specs:

  - feel more expensive than 60$
  - when on diode range, it still beeps if you short the probes, like in continuity mode. Switch-mode power supply repairs got easier.
  - discharges capacitors under test
  - easy hacks available for Auto-Power-Off and Backlight
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: UPz on April 24, 2013, 05:22:02 pm
Hi guys  :)
This is my first post here!

I'm having a bit of trouble with my UT61E.

Using the UT61E user interface program V4.01 (UT61E.exe), and loging data to the PC in sample intervals (15 sec for example), I end with time inconsistent results in the log file. Sometimes it jumps one second, sometimes it jumps 9 minutes of log.

I have tested with a third party software, called UltraDMM (v1.0.3), and it has the same behaviour.
I've tested without the sample interval option checked and somehow I got solid two measurements per second...

Two screenshots:
(http://i.imgur.com/ZaylgYr.png)

(http://i.imgur.com/RoP7lFM.png)


I'm using the RS232C cable, and my PC runs on Win7.
Have you any idea of what can be happening?

Thanks in advance!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Bored@Work on April 24, 2013, 05:55:03 pm
Hi guys  :)
This is my first post here!

I'm having a bit of trouble with my UT61E.

Using the UT61E user interface program V4.01 (UT61E.exe), and loging data to the PC in sample intervals (15 sec for example), I end with time inconsistent results in the log file. Sometimes it jumps one second, sometimes it jumps 9 minutes of log.


Since the UT61E can't be programmed, i.e. the data communication is one-way UTE61e --> PC only, and since it therefore always sends with a fixed sample interval, which the PC software can't change, the reason for the occasional 1 second jumps seem obvious. Any sample interval that isn't a multiple of the UT61E's native data rate (probably 2 sec.) will sooner or later end up with such a jump, due to accumulating errors when the software tries to map the time of received data to the nearest time for the intended sample rate. Even a sample rate set to a multiple of the native sample rate will sooner or later have such a jump, depending how the UT61E's clock rate and the Windows timer differ.

Nine minutes of data loss, however, experienced with two different pieces of software, means there is something wrong outside of the applications. E.e. the driver, Windows, hardware ...

Anyhow, you could try yet another software, http://www-user.tu-chemnitz.de/~heha/hs_freeware/UNI-T/dmm.zip (http://www-user.tu-chemnitz.de/~heha/hs_freeware/UNI-T/dmm.zip) Don't be surprised that the software is so small, the guy who did that software doesn't believe in .NET rubbish. Maybe that software does what you want.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on April 24, 2013, 08:07:29 pm
Hi guys  :)
This is my first post here!

I'm having a bit of trouble with my UT61E.

Using the UT61E user interface program V4.01 (UT61E.exe), and loging data to the PC in sample intervals (15 sec for example), I end with time inconsistent results in the log file. Sometimes it jumps one second, sometimes it jumps 9 minutes of log.


Since the UT61E can't be programmed, i.e. the data communication is one-way UTE61e --> PC only, and since it therefore always sends with a fixed sample interval, which the PC software can't change, the reason for the occasional 1 second jumps seem obvious. Any sample interval that isn't a multiple of the UT61E's native data rate (probably 2 sec.) will sooner or later end up with such a jump, due to accumulating errors when the software tries to map the time of received data to the nearest time for the intended sample rate. Even a sample rate set to a multiple of the native sample rate will sooner or later have such a jump, depending how the UT61E's clock rate and the Windows timer differ.

Nine minutes of data loss, however, experienced with two different pieces of software, means there is something wrong outside of the applications. E.e. the driver, Windows, hardware ...

Anyhow, you could try yet another software, http://www-user.tu-chemnitz.de/~heha/hs_freeware/UNI-T/dmm.zip (http://www-user.tu-chemnitz.de/~heha/hs_freeware/UNI-T/dmm.zip) Don't be surprised that the software is so small, the guy who did that software doesn't believe in .NET rubbish. Maybe that software does what you want.

I have done a good bit of logging since I got my UT-61E around New Year time.  I can confirm that Bored@Work is spot on for both counts.

I deal with the +-1 tick by adding a "calculated time" column in the spreadsheet, and made that
=CellAbove + N Seconds  (where N is my sampling interval)
Of course, the first row has no CellAbove, you have to copy-paste the start time onto that cell.

You will find that a few rows down, it will get out of sync (calculated time != time stamp) and then in a few more rows it will get back in sync, then later, it will be out again and back again.  The time delta could be 2 clock ticks: Mathematics saids when you truncate and round, you have a +-1 on each.  When PC and UT both have a +-1, your max error is 2.

I just add that extra column and plot the graph based on that extra.

* * *
As to the 9 minute lost...

After encountering the same thing, I ignore it at first, then I saw it attempting to download new anti-virus file while logging data and not having a good time doing it.  So, now when I am logging, I disable WiFi and hard-IP the NIC with no gateway and no DNS.  Hard-IP means type it in yourself.  These auto-updates are deadly.  Flash, JAVA, whatever.  With the NIC having no DNS and no gateway, I can talk to it inside (so I can monitor progress remotely) inside the house, but it has no official way to talk to the outside world.  It has not happened since.

If you are not sure what IP to use, turn your machine on normally and do a:
ipconfig /all
It will tell you what IP you are using.  You can use the same IP and just erase the gateway and DNS entry.  That IP assigned to your machine will stay with your machine for (typical) 24 hours).  Without gateway and DNS, it will disable most normal network connections to the outside world.  Hackers may hard-code their target IP (no need for DNS) and try various gateways (typical setup makes it easy to find).  Those you will need a firewall setting to stop which is hard, or just pull the darn RJ45 plug which is easy.  Make sure you set it back when done.  The hacker's communication target IP is likely not their own IP but a zombie machine.

Rick
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on April 26, 2013, 06:34:05 pm
You seem to be rather knowledgeable on the topic of network security ... studied network security?  :P
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on April 26, 2013, 06:43:08 pm
You seem to be rather knowledgeable on the topic of network security ... studied network security?  :P

If you are referring to me, the answer is NO and YES.

No, I do not know a lot of about network security.  Network is something that cannot be secured 100%.  The more I know, the less secure I feel.

Yes, I studied enough to know the basics. On multiple occasions, I was either responsible for the operation of a network for a group or responsible for network for an enterprise (>100 nodes, <5000 nodes) - and of course, my wife appointed me the official "tech support" at home.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on May 07, 2013, 02:41:03 pm
Hi, question for the Uni-T UT61E.

When you switch on to Volts the display will initialize and show 0.000V but when you switch on
and have the blue button pressed the display will show 0.0000V until you let go the blue button.

Does anybody know if there is a hidden mode or some hidden function?
For example in the UT71E if you do the same, the multimeter will start with one digit less resolution,
but with a very fast refresh.   :-+

Thanks.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dr_p on May 07, 2013, 07:11:36 pm
mine always initialises in 0.0000V (5 digits)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on May 07, 2013, 07:50:43 pm
Strange. 
After initialization does it stay with 5 digits?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on May 07, 2013, 08:33:02 pm
Same here, shows all 5 digits.

There are a couple or so undocumented features but they're documented in the IC datasheet (the IC used by the multimeter).

See the datasheet, from 3.1 forward, all kinds of things you can do in combination with the HOLD button : http://www.cyrustek.com.tw/spec/ES51922.pdf (http://www.cyrustek.com.tw/spec/ES51922.pdf)   

Plus there's a mention a few pages before saying if you keep hold pressed for 2 seconds while switching the meter on will keep all lcd segments lit until you hit hold again.



Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on May 08, 2013, 12:48:05 am
Mine switch on to 0.0000 Volt  (5 digits).  With test leads touching, it shows and stay 0.0000V.  When the leads are not touching, it will show random milli-volts as I move my body around which I assume to be it picking up static electricity and my body's field.

I am guessing: I suspect if it picks up the random static electricity over 2.2V it would go to and the range over 2.2V volt which would be 4 digits.

The biggest random volts I've seen is 0.1v (100mV) range, no where near switching to > 2.2V, but I can see it could happen if you are wearing wool and on carpeting.  I am not even sure if it will stay on that range after just a brief shot over 2.2V.

Rick

EDIT/Update:
I tried to reproduce a higher random voltage caused by static electricity on start up.  I used a 9v battery brushing by the test leads as it was powering up.  It went into the over 2.2v range reducing it to 4 digits (9.xxxx) for a brief moment.  But it settles back down to below 2.2V range displaying 0.0000 (5 digits).  So, at least for my version of firmware, my guess of brief static electricity causing it to change range is not on target.  Even if that happened, it came back down on its own.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: try on June 01, 2013, 07:45:01 pm
Hi sdttn!

How did you suppress the original "Hold"-function?
Did you connect the the "Hold"-Pin to the "Range"-Pin?

How much current do you draw from BKOUT?
How do you know if this is just a logical output or an output that allows some current flowing?
I don't find any answer in the specsheet from Cyrustek.

Regards
try

Thanks for your reply.

By the way the DMM has not backlight function.
But the chip (ES51922 (http://www.cyrustek.com.tw/spec/ES51922.pdf)) supports backlight function. The HOLD button is useless for me so I decided to use this button as backlight ON/OFF button.


(http://img841.imageshack.us/img841/514/mhfuq.jpg)

(http://img839.imageshack.us/img839/3936/5wb1vc.jpg)

Short youtube video. (https://www.youtube.com/watch?v=Ud6ITlbw_QY#)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on June 04, 2013, 07:46:30 pm
I just cut hold button trace.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on June 04, 2013, 07:58:37 pm
If you just cut the hold button trace and leave it disconnected, you loose the valuable feature of the delay hold. When you press the hold button for a few seconds the meter goes into a timed hold mode. During this time you can connect to the voltage you want to measure and then wait for the beep. At that time the meter will hold the value and you get almost the same benefit as an auto-hold like some Flukes have
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dr_p on June 05, 2013, 07:51:22 am

Also if you do the "photodiode-to-auto-power-off-from-RS232-handshake" hack you also lose the ability to wake up the meter from auto power off. It automatically wakes up in display HOLD, so you have to press the hold button to cancel that. If you switch ranges it goes to delay HOLD, so you'll have to turn it off, then on again via the rotary switch.


But you can maybe add a MCU and implement a dual function for the HOLD button: single press = backlight command, long press = delay HOLD. You lose the simple instant-display HOLD function, but that's useless anyway IMHO.


The auto-power off hack is the best bang for your buck, so to speak, because you lose no functionality of the meter. Only when you connect RS232 adapter, the meter disables serial communication and enables 15min auto power off.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on June 05, 2013, 04:35:36 pm
If Uni-T had not been cheap on the input protection, had configured the data cable for the auto power off switching, and supplied a USB cable instead, they could be sold for $75 and they would still sell like crazy. The backlight would be quite a bit more work to rework the design.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on June 07, 2013, 04:27:56 am
They already sell like hotcakes ... and no i don't mind the 50$ bracket. I rather they stayed there
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on June 07, 2013, 03:55:14 pm
If Uni-T had not been cheap on the input protection, had configured the data cable for the auto power off switching, and supplied a USB cable instead, they could be sold for $75 and they would still sell like crazy. The backlight would be quite a bit more work to rework the design.

Yeah, I would have like to see back-light and auto power off.  The USB v RS232 cable, I can see pluses on both sides.  But back  light and auto-power-off, I would have paid $10 for that two features.

Another nice feature I would like to have the rubber part of the housing a removable-hoster like construct similar to the Flukes.

What they should put out are:

>>  a 61E+ model.  $10 for that extra three features.
>> And a 61E+Super with BL/APO feature with 40,000 or 50,000 counts, max/min (with peak), better burden voltage for current measurement, 2Amp range.  220mA with a lousy burden voltage now is just too small (and burden voltage too high)  to be useful.
>>  And a 61E+Ultra with +Super, temperature, inductance, auto 6sec hold (as it is now) or steady-read then hold, and much better burden voltage for current.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Legit-Design on June 08, 2013, 03:39:48 am
>>  a 61E+ model.  $10 for that extra three features.
>> And a 61E+Super with BL/APO feature with 40,000 or 50,000 counts, max/min (with peak), better burden voltage for current measurement, 2Amp range.  220mA with a lousy burden voltage now is just too small (and burden voltage too high)  to be useful.
>>  And a 61E+Ultra with +Super, temperature, inductance, auto 6sec hold (as it is now) or steady-read then hold, and much better burden voltage for current.

Get UT-61D,  you gain backlight, auto power-off, Superlow burden voltage (lowest resistance in Daves 100$ multimeter shootout), also cheap for around 50$ on ebay. Plus more multimeters is always priceless and enables to do alot more things. Even if you lose some resolution (maybe some accuracy too) you still have UT-61E to take care of those needs. Unless they come out with a multimeter with multiple isolated channels, those things are hard to beat when combined.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on June 08, 2013, 04:23:18 am

Get UT-61D,  you gain backlight, auto power-off, Superlow burden voltage (lowest resistance in Daves 100$ multimeter shootout), also cheap for around 50$ on ebay. Plus more multimeters is always priceless and enables to do alot more things. Even if you lose some resolution (maybe some accuracy too) you still have UT-61E to take care of those needs. Unless they come out with a multimeter with multiple isolated channels, those things are hard to beat when combined.

The main thing against all the other models (except E) in the UT61 series is how slow they are. Continuity and autorangong seem painfully slow on the A-D models.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on June 08, 2013, 05:20:34 am
...Plus more multimeters is always priceless and enables to do alot more things....Unless they come out with a multimeter with multiple isolated channels, those things are hard to beat when combined.

I am reasonably happy with the 61E.  I already have 3 others - 2 radioshack and a DT830B.  But I actually was thinking about getting a couple more  DT830B's when I was playing around with boost circuits:
In Volt, in current, out Volt, out current, drain current, that is 4 right there.  I could use another one to do adhoc readings.

One of my 4 is a DT830B, $6 DMM, not bad.  I use it as my volt meter for my PSU.  It actually performs better than the other cheapos from Radio Shack (4-8 years old).  So I was considering getting a pair of DT830B.  But I hate all those stuff on my table leaving me so little space.

I would not invest in another mid-low end DMMs.  If I would get more DMMs, I will probably aim for a higher end ones or real cheapies.  Mean time, I just got my ATMega328 as Volt/Current meter working on a breadboard and ordered parts to transfer it to PCB.  I divided up the 6 ADC's as 3 pairs of volt+current (switch-selectable) 0 - 5/15/30Volt and fixed 0-4Amp (using a 0.1ohm as current sense and amplified with OpAmp).  The two pairs I have working gets me +-1% to 4% accuracy.  Not bad when I have not yet calibrated them yet.  After I get the parts, I can get the 3rd pair working, transfer it to PCB, and then I'll do some software tricks (the ADC under-reads at low ranges).  If I can bring it closer to 1-2% using my UT61E as "accurate" reference, I just may end up using the ATMega as my PSU's volt+current.  All three channels shares common ground, so it took me a while to figure out how I would make that work for me.  If the thing works (at +- 1-2%), I don't need the DT830B's as volt/current meter.  If it doesn't, well, I learned a lot trying to get it working so far.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: don.r on June 13, 2013, 11:02:36 pm
Just got the meter today from Franky. Thanks again, Franky! The autoranging is really slow, as noted above. The probes are... well... Uni-T probes... crap.  :-- The meter really needs a backlight. Other than that, the display is crisp, the readings are accurate (when they get there) and getting 5 digits is great for less than $60.  :-+ Still waiting on my eBay UT136B for a nice comparison.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on June 13, 2013, 11:05:48 pm
61E? Slow autoranging? It's pretty fast compared to most meters <$200.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: don.r on June 13, 2013, 11:12:25 pm
61E? Slow autoranging? It's pretty fast compared to most meters <$200.

In ohms it seems to jump all over before settling down after 2 or 3 seconds. It could be the god-awful probes.  :palm: They really are bad. Like $10 meter bad.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on June 13, 2013, 11:35:07 pm
61E? Slow autoranging? It's pretty fast compared to most meters <$200.

In ohms it seems to jump all over before settling down after 2 or 3 seconds. It could be the god-awful probes.  :palm: They really are bad. Like $10 meter bad.

Yes, the probes suck. This is known. Clean them.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: don.r on June 13, 2013, 11:43:25 pm
61E? Slow autoranging? It's pretty fast compared to most meters <$200.

In ohms it seems to jump all over before settling down after 2 or 3 seconds. It could be the god-awful probes.  :palm: They really are bad. Like $10 meter bad.

Yes, the probes suck. This is known. Clean them.

I did clean them with IPA several times. I'll just use better probes. It seems to work fine with the Pomona's so its not the meter, just the probes making me think its the meter.  :phew:
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on June 14, 2013, 12:47:55 am
When cleaning the probes, you need to get a little aggressive. You can use chrome cleaner or Brasso. If you use isopropanol, then you should use fine steel wool to clean them. The plastic mold release and/or any plastic coating that might be there from molding the handles needs to be physically broken up to remove it. Do not use sand paper or abrasive pad as this will scratch and pit the plating on the probe tips and cause corrosion in the end.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Brendan L on June 17, 2013, 06:06:32 pm
How can a reading of less than zero ohms be achieved ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: HKJ on June 17, 2013, 06:10:45 pm
How can a reading of less than zero ohms be achieved ?

A DMM uses a constant current generator and measures the voltage across the resistor. Any external voltage will upset the reading, i.e. a negative external voltage will (usual) show negative ohms.
A few DMM's can compensate for small external voltages.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: T4P on June 18, 2013, 02:51:52 am
Apart from Agilent's magic volt bias canceller  ::)  :P
I certainly find that function very useful ... VERY USEFUL.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on August 15, 2013, 06:34:47 am
In case anyone cares, I did a quick test hooking my "new" oscilloscope up to the ut61e. Below 200nF it uses a clear square wave. Above this, it registers no load so it shows nothing. I preceded to add a 2200uF "load" which shows a clear 1Hz pulse train

Sent from my EVO using Tapatalk 4

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: cosmos on August 15, 2013, 07:28:55 am
The "new" scope picture looks like it came from a LeCroy 7200, a heavy power hungry beast sounding like a pair of 747s at takeof.
Turning off my 1kW electric oven and using the 7200 instead actually increased the room temperature.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on August 15, 2013, 03:26:46 pm
Close, the "new" scope is the apparently quieter LeCroy 9410 with all options (including FFT). This one isn't that loud at all, more of a gentle purr. I picked it up locally for $120 with two tek 10x probes thrown in for free.

Sent from my EVO using Tapatalk 4

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: notzippy on August 20, 2013, 08:22:22 pm
Noticed on the website the UT61E is supposed to have a backlight http://www.uni-trend.com/UT61E.html (http://www.uni-trend.com/UT61E.html) , although the manual indicates otherwise. anyone know what is correct ? Looking at the first post it appears there is no backlight, but things can change..

thx
Nz
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on August 20, 2013, 08:55:26 pm
The UT61E does not have a back light.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on August 20, 2013, 08:57:20 pm
It also says sleep mode 15 minutes while there's no such mode. 

No, imho, it's just bad data. The english version of the site is not really updated, check the chinese version always:

http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.uni-trend.com.cn%2Fcp-show.asp%3Fyy%3D%25D6%25D0%25CE%25C4%26ProductNO%3D481&act=url (http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.uni-trend.com.cn%2Fcp-show.asp%3Fyy%3D%25D6%25D0%25CE%25C4%26ProductNO%3D481&act=url)

(^^Google Translate above) No backlight and sleep here.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Electro Fan on August 20, 2013, 09:31:26 pm
...Plus more multimeters is always priceless and enables to do alot more things....Unless they come out with a multimeter with multiple isolated channels, those things are hard to beat when combined.

I am reasonably happy with the 61E.  I already have 3 others - 2 radioshack and a DT830B.  But I actually was thinking about getting a couple more  DT830B's when I was playing around with boost circuits:
In Volt, in current, out Volt, out current, drain current, that is 4 right there.  I could use another one to do adhoc readings.

One of my 4 is a DT830B, $6 DMM, not bad.  I use it as my volt meter for my PSU.  It actually performs better than the other cheapos from Radio Shack (4-8 years old).  So I was considering getting a pair of DT830B.  But I hate all those stuff on my table leaving me so little space.

I would not invest in another mid-low end DMMs.  If I would get more DMMs, I will probably aim for a higher end ones or real cheapies.  Mean time, I just got my ATMega328 as Volt/Current meter working on a breadboard and ordered parts to transfer it to PCB.  I divided up the 6 ADC's as 3 pairs of volt+current (switch-selectable) 0 - 5/15/30Volt and fixed 0-4Amp (using a 0.1ohm as current sense and amplified with OpAmp).  The two pairs I have working gets me +-1% to 4% accuracy.  Not bad when I have not yet calibrated them yet.  After I get the parts, I can get the 3rd pair working, transfer it to PCB, and then I'll do some software tricks (the ADC under-reads at low ranges).  If I can bring it closer to 1-2% using my UT61E as "accurate" reference, I just may end up using the ATMega as my PSU's volt+current.  All three channels shares common ground, so it took me a while to figure out how I would make that work for me.  If the thing works (at +- 1-2%), I don't need the DT830B's as volt/current meter.  If it doesn't, well, I learned a lot trying to get it working so far.

Please keep us posted on how your Atmega328 meter reading project is going - I'm sure some folks would be up for trying your design if you want to share it.  Thx
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: notzippy on August 20, 2013, 09:34:44 pm
It also says sleep mode 15 minutes while there's no such mode. 

No, imho, it's just bad data. The english version of the site is not really updated, check the chinese version always:

http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.uni-trend.com.cn%2Fcp-show.asp%3Fyy%3D%25D6%25D0%25CE%25C4%26ProductNO%3D481&act=url (http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.uni-trend.com.cn%2Fcp-show.asp%3Fyy%3D%25D6%25D0%25CE%25C4%26ProductNO%3D481&act=url)

(^^Google Translate above) No backlight and sleep here.
Thanks, the picture on their site certainly looks like its backlight. Although your right about the specs stating "background light" is definitely not checked. Not really a deal breaker for me, just trying to get the best bang for the buck these days..

Nz
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on August 21, 2013, 03:53:50 am
...Plus more multimeters is always priceless and enables to do alot more things....Unless they come out with a multimeter with multiple isolated channels, those things are hard to beat when combined.

I am reasonably happy with the 61E.  I already have 3 others - 2 radioshack and a DT830B.  But I actually was thinking about getting a couple more  DT830B's when I was playing around with boost circuits:
In Volt, in current, out Volt, out current, drain current, that is 4 right there.  I could use another one to do adhoc readings.

One of my 4 is a DT830B, $6 DMM, not bad.  I use it as my volt meter for my PSU.  It actually performs better than the other cheapos from Radio Shack (4-8 years old).  So I was considering getting a pair of DT830B.  But I hate all those stuff on my table leaving me so little space.

I would not invest in another mid-low end DMMs.  If I would get more DMMs, I will probably aim for a higher end ones or real cheapies.  Mean time, I just got my ATMega328 as Volt/Current meter working on a breadboard and ordered parts to transfer it to PCB.  I divided up the 6 ADC's as 3 pairs of volt+current (switch-selectable) 0 - 5/15/30Volt and fixed 0-4Amp (using a 0.1ohm as current sense and amplified with OpAmp).  The two pairs I have working gets me +-1% to 4% accuracy.  Not bad when I have not yet calibrated them yet.  After I get the parts, I can get the 3rd pair working, transfer it to PCB, and then I'll do some software tricks (the ADC under-reads at low ranges).  If I can bring it closer to 1-2% using my UT61E as "accurate" reference, I just may end up using the ATMega as my PSU's volt+current.  All three channels shares common ground, so it took me a while to figure out how I would make that work for me.  If the thing works (at +- 1-2%), I don't need the DT830B's as volt/current meter.  If it doesn't, well, I learned a lot trying to get it working so far.

Please keep us posted on how your Atmega328 meter reading project is going - I'm sure some folks would be up for trying your design if you want to share it.  Thx

Sure, I will share what I learn.  I am learning some interesting stuff at least for me the newbie.

I am working on it on my spare time, so it will take at least another one or two months.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: george graves on August 21, 2013, 04:24:26 am
The UT61E does not have a back light.

I was planning on adding one - but the display is so sharp and clear, that you can see it in even the dimmest of rooms.  It's better then a fluke 87-5.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: algorath on October 08, 2013, 03:03:41 pm
i recently had to open mine up for repair. the A range was somehow shorted with the Hz, or Ohms i dont remember. turns out there was some sort of debree (im guessing from the pcb) that got stuck on the range switch. also one of the range springs was kinda corroded  :--
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: form on October 08, 2013, 05:58:34 pm
Has anybody seen software-bugs on that DMM, too?
Sometimes the autoranging fails and instead of changing the range, the displayed value is just wrong.
Very dangerous...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on October 08, 2013, 06:03:21 pm
Has anybody seen software-bugs on that DMM, too?

It has no software.

Quote
Sometimes the autoranging fails and instead of changing the range, the displayed value is just wrong.
Very dangerous...

I have yet to have this occur.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on October 08, 2013, 09:41:08 pm
Has anybody seen software-bugs on that DMM, too?

It has no software.

Quote
Sometimes the autoranging fails and instead of changing the range, the displayed value is just wrong.
Very dangerous...

I have yet to have this occur.

The update rate is 2 times per second on the UT61E. 
When changing ranges, it happens that one update is messed up (sometimes it just moves the dot instead of dropping a decimal, for example when going from 22.124v to 25.12v, you get 251.24 or something like that). But this is basically shown for half a second (one update) with the next update half a second later, the correct value is shown.

Once you get used to it, it's not dangerous at all and these erroneous values can be easily scrubbed out of log file, if you do data logging.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on October 08, 2013, 09:45:04 pm
Has anybody seen software-bugs on that DMM, too?

It has no software.

Quote
Sometimes the autoranging fails and instead of changing the range, the displayed value is just wrong.
Very dangerous...

I have yet to have this occur.

The update rate is 2 times per second on the UT61E. 
When changing ranges, it happens that one update is messed up (sometimes it just moves the dot instead of dropping a decimal, for example when going from 22.124v to 25.12v, you get 251.24 or something like that). But this is basically shown for half a second (one update) with the next update half a second later, the correct value is shown.

Once you get used to it, it's not dangerous at all and these erroneous values can be easily scrubbed out of log file, if you do data logging.

I'm well aware of that particular issue, that is not what he described.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: safetyfirst on October 09, 2013, 03:28:37 am
See page 41 of the Uni-T Series 61x Operating Manual.  The 61E does NOT have a Backlight or a Sleep mode / Auto Power Off (APO).  I cannot post the entire manual as the pdf is almost 5MB.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on October 09, 2013, 03:32:50 am
The UT61E is a nice meter for the price, but don't expect too much out of it. For a 22,000 count meter with many good features it is a good buy. Keep it on the bench and don't even show anything high energy or high voltage. If you want something safer, then you have to do with lower specs or higher price to keep the same specs.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on October 09, 2013, 04:06:12 am
Has anybody seen software-bugs on that DMM, too?
Sometimes the autoranging fails and instead of changing the range, the displayed value is just wrong.
Very dangerous...

Nobody else has ever experienced anything like that. There could be a fault with your meter. Did you capture it on video?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: algorath on October 09, 2013, 06:49:43 pm
the lack of backlight and auto power off are really strange. what´s that cost, 1$? personally i don´t miss a backlight too much. but i´ve had my batterie drained a couple of times cause i left the damn thing on for 2 days straight :) good thing i got recharchable 9vs
btw, there´s an easy tutorial on yt on how to add backlight
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: user4963 on October 15, 2013, 01:24:35 pm
Hi .
Please help me. I dont know. it: C11b*,C11a*,C10a*,C9a*,C9b*,C8a*,C8b*      :wtf:             ?
and If the circuit diagram of this model. Do you know download on
(http://s24.postimg.org/mnhyww18h/image.jpg) (http://postimg.org/image/mnhyww18h/)
Title: Re: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on October 15, 2013, 03:20:25 pm
Hi .
Please help me. I dont know. it: C11b*,C11a*,C10a*,C9a*,C9b*,C8a*,C8b*      :wtf:             ?
and If the circuit diagram of this model. Do you know download on
(http://s24.postimg.org/mnhyww18h/image.jpg) (http://postimg.org/image/mnhyww18h/)
If I remember correctly it appears the * means alternate locations. I don't know if they are there to allow them to source cheaper parts or what but often they are not populated.

Sent from my EVO 4G LTE using Tapatalk

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on October 15, 2013, 04:24:04 pm
I would guess that they are values that are subject to change or adjustment for trimming accuracy. Here is the schematic.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: user4963 on October 15, 2013, 05:41:19 pm
I would guess that they are values that are subject to change or adjustment for trimming accuracy. Here is the schematic.

That not schematic. ?t ic 1778 ? and How do I find the values ??of these elements.
Multimeter shows wrong value. 1K play in resistance measurement.

Please somebody help me. How do find ic 1778 schematic ( or ic 1778 datasheet )
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on October 15, 2013, 05:48:43 pm
That is the schematic. I don't know what you are asking.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Legit-Design on October 15, 2013, 06:08:48 pm
I would guess that they are values that are subject to change or adjustment for trimming accuracy. Here is the schematic.

That not schematic. ?t ic 1778 ? and How do I find the values ??of these elements.
Multimeter shows wrong value. 1K play in resistance measurement.

Please somebody help me. How do find ic 1778 schematic ( or ic 1778 datasheet )

To my knowledge "ic 1778", that black thing next to those smd capacitors, is precision hybrid resistor network or similar. Please take  picture of the resistor you are measuring and how you are measuring it. I think the problem might lie in your measurements also. If you measure 5% resistor, its value might be +-5% of what is actually says on the resistor. Also don't measure resistors directly in circuit it might cause faulty readings. Since there is a language barrier taking pictures might be easiest thing to do.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: user4963 on October 15, 2013, 06:10:14 pm
That is the schematic. I don't know what you are asking.

The diagram C11a*,C11b*,.... no.I'm looking for these values
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: user4963 on October 15, 2013, 06:29:11 pm
I would guess that they are values that are subject to change or adjustment for trimming accuracy. Here is the schematic.

That not schematic. ?t ic 1778 ? and How do I find the values ??of these elements.
Multimeter shows wrong value. 1K play in resistance measurement.

Please somebody help me. How do find ic 1778 schematic ( or ic 1778 datasheet )

Thank you
10k resistor.. Multimeter 9.205 measure vicinity

To my knowledge "ic 1778", that black thing next to those smd capacitors, is precision hybrid resistor network or similar. Please take  picture of the resistor you are measuring and how you are measuring it. I think the problem might lie in your measurements also. If you measure 5% resistor, its value might be +-5% of what is actually says on the resistor. Also don't measure resistors directly in circuit it might cause faulty readings. Since there is a language barrier taking pictures might be easiest thing to do.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: user4963 on October 15, 2013, 06:39:10 pm
measure the values ??of the capacitor can write one of these?

Please
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on October 15, 2013, 07:49:59 pm
I might be able to do that tomorrow
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: user4963 on October 16, 2013, 02:06:32 pm
thank you.Lightages
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on October 24, 2013, 11:23:15 pm
...Plus more multimeters is always priceless and enables to do alot more things....Unless they come out with a multimeter with multiple isolated channels, those things are hard to beat when combined.

I am reasonably happy with the 61E.  I already have 3 others - 2 radioshack and a DT830B.  But I actually was thinking about getting a couple more  DT830B's when I was playing around with boost circuits:
In Volt, in current, out Volt, out current, drain current, that is 4 right there.  I could use another one to do adhoc readings.

One of my 4 is a DT830B, $6 DMM, not bad.  I use it as my volt meter for my PSU.  It actually performs better than the other cheapos from Radio Shack (4-8 years old).  So I was considering getting a pair of DT830B.  But I hate all those stuff on my table leaving me so little space.

I would not invest in another mid-low end DMMs.  If I would get more DMMs, I will probably aim for a higher end ones or real cheapies.  Mean time, I just got my ATMega328 as Volt/Current meter working on a breadboard and ordered parts to transfer it to PCB.  I divided up the 6 ADC's as 3 pairs of volt+current (switch-selectable) 0 - 5/15/30Volt and fixed 0-4Amp (using a 0.1ohm as current sense and amplified with OpAmp).  The two pairs I have working gets me +-1% to 4% accuracy.  Not bad when I have not yet calibrated them yet.  After I get the parts, I can get the 3rd pair working, transfer it to PCB, and then I'll do some software tricks (the ADC under-reads at low ranges).  If I can bring it closer to 1-2% using my UT61E as "accurate" reference, I just may end up using the ATMega as my PSU's volt+current.  All three channels shares common ground, so it took me a while to figure out how I would make that work for me.  If the thing works (at +- 1-2%), I don't need the DT830B's as volt/current meter.  If it doesn't, well, I learned a lot trying to get it working so far.

Please keep us posted on how your Atmega328 meter reading project is going - I'm sure some folks would be up for trying your design if you want to share it.  Thx

As promised...

https://www.eevblog.com/forum/microcontrollers/an-implementation-of-atmega328-volt-logger-the-dinometer-a-learning-project/ (https://www.eevblog.com/forum/microcontrollers/an-implementation-of-atmega328-volt-logger-the-dinometer-a-learning-project/)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Benik3 on October 31, 2013, 05:52:40 pm
I suppose that it's the best choice under 75USD? :)

Only thing which disappoint me is the resistance for measuring of high currents :/
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on October 31, 2013, 08:32:13 pm
user4963:

Sorry I haven't had the time to check the parts for you yet. I will get to it soon.

Quote
I suppose that it's the best choice under 75USD?

I am not sure I would say it is the best choice for under $75, but it is one of the best. There are the Digitek DT4000ZC and the DT2843R which are very good values for the money too. The DT2843R measures RMS AC+DC whereas the UT61E only does AC. The DT2843R has very slow continuity test but has very low burden voltage on the current measurements. The best buy depends on your needs between these.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Benik3 on October 31, 2013, 09:16:32 pm
OK thanks, I will look at it :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on October 31, 2013, 09:28:29 pm
Actually, If you are in the US and willing to spend $78, have a look at this:
https://www.eevblog.com/forum/buysellwanted/great-deal-on-amprobe-am-270- (https://www.eevblog.com/forum/buysellwanted/great-deal-on-amprobe-am-270-)!!!-us-only-(/
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Benik3 on October 31, 2013, 10:06:26 pm
I'm from Czech Republic :/
But how much cost normal shipping from US to CZ? If there will be someone to buy it for me... :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on November 01, 2013, 04:57:55 am
This is why everyone needs to put their country in their profile, or say what country they are from before asking anything.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: tmammela on November 01, 2013, 09:47:32 am
Is it possible to calibrate resistance or current measurement in this meter? There seems to be many pots inside it but I've only seen discussion about dcv calibration. I have a dmmcheck plus incoming so I would have all needed references.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: george graves on November 01, 2013, 10:23:31 am
WOuld like to know as well.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Benik3 on November 01, 2013, 11:11:07 am
This is why everyone needs to put their country in their profile, or say what country they are from before asking anything.

I thought that I choose it in registration, but now I see that I don't have the flag on my profile.
Never mind, repaired :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ModemHead on November 01, 2013, 01:27:22 pm
Is it possible to calibrate resistance or current measurement in this meter? There seems to be many pots inside it but I've only seen discussion about dcv calibration. I have a dmmcheck plus incoming so I would have all needed references.
In my experience, it's not common to see calibration adjustments for resistance or current on manually-calibrated (trim-pot) handhelds.  Closed-case calibration units can of course calibrate any function/range using stored offsets.

A dual-slope integrating A/D converter is by its nature ratio-metric. Measuring resistance is done by passing a current through a reference resistor and the unknown resistance. The ADC measures the ratio of the voltages across the two resistors by switching it's reference input to the voltage across the known resistance.  The ratio of the voltages is also the ratio of the resistances, since the current is the same.

This means the accuracy of the resistance range is based mostly on the tolerance and tempco of the resistors used as the 'known'.  These are often dual-purposed from the voltage divider.  How close the multimeter comes to a known resistance measurement is a good indication of the quality of the parts in the front end, but not of the DCV calibration.  The DCV calibration is usually done by tweaking the voltage reference, and that isn't even used during resistance measurement.

For current ranges, it's measuring the voltage across the shunts, so both the DCV calibration and the tolerance and tempco of the shunts come into play.  Calibrating just the current without affecting voltage would require tweaking the shunts.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: tmammela on November 01, 2013, 03:28:10 pm
For current ranges, it's measuring the voltage across the shunts, so both the DCV calibration and the tolerance and tempco of the shunts come into play.  Calibrating just the current without affecting voltage would require tweaking the shunts.

Thank you. So no resistance calibration, that's fine. So ideally if I calibrate dcv it also calibrates current?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ModemHead on November 01, 2013, 03:53:52 pm
So no resistance calibration, that's fine. So ideally if I calibrate dcv it also calibrates current?

I took a look at the UT61E schematic and I can't spot any trim pots that would affect the voltage off the shunts.

However, I do see a 10K pot in line with the ohms voltage sense (VR3).  Not sure how much effect that would have on a high impedance input, but it may tweak the ohms readings?

Be careful with your adjustments, you don't want to make it worse. :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mrflibble on December 03, 2013, 04:02:51 am
Mmmh, quick check on ebay shows they go for < $60 these days. Is the UT61E still the budget model to go for, or are there other nice deals to be aware of? I noticed the Digitek DT-2843R and Digitek DT-4000ZC being mentioned as well, but those don't quite have the resolution of the UT61E...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on December 04, 2013, 04:10:13 am
Still the cheapest option for a new sturdy 4 1/2 digit TRMS meter with autoranging. It is not a perfect meter by any means, but quite usable and probably the best value for a hobbyist on a budget.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on December 04, 2013, 05:16:10 am
Still the cheapest option for a new sturdy 4 1/2 digit TRMS meter with autoranging. It is not a perfect meter by any means, but quite usable and probably the best value for a hobbyist on a budget.

I agree.  Very good meter for the money.  I did very careful research before I purchase it.  I was not sure that this time around in returning to play with EE if my interest would not fizzle out as it did the last couple of times, so I was not willing to spend a lot of money with a new meter.  I went the low cost route.

Having own the UT61E for a year now, I can say I am very pleased with it.  I would have like it had it been say 60,000 count, twice as accurate, backlid, auto-off... etc, etc, etc.  But that would have been 3x 4x or 10x what I was would have to spend.

Good value for the money is important in my decision.  My diddling around requires nothing more that a percent or two accuracy.  This far exceeded my need and at a very low cost.  So in my case, I am very pleased with it.

Rick
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mrflibble on December 04, 2013, 10:16:52 am
Thanks! Looks like the UT61E is the one to go for. Or rather, it was the one to go for right now, and has become the one to maybe go for in the future. It's bloody typical. You look for a used 5 1/2 digit meter for quite some time, cannot find it for a decent price, and then decide ah fuck it I'll go for a new 4 1/2 digit handheld meter. So you invest some time into researching the various option, decide on a certain meter, do your last sanity checks (posting in this thread) and then ... an affordable 5 1/2 digit meter pops up. Isn't that always the way... :-DD

So I picked up an HP 3478A for $150 shipped.  :-DMM Not nearly as cheap as some of those  :rant: cheap offerings I sometimes see in the US, but such is life.

Chances are I will still get me a UT61E since it does look like a pretty nice meter, but the purchasing date suddenly got pushed back. :P Relative importance and allocation of limited moneys and all that.

Edit: grammar happens to people who proofread.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on December 12, 2013, 08:50:16 am
The UT61E has a strange 'Peak Hold' implementation.
Usually on other meters, 'Peak Hold' displays very fast measurements of the AC sine wave positive peak voltage, with a max/min around that voltage.
On the 61E, 'Peak Hold' goes through a calibration first and then displays The Max (positive) and Max (Negative) of the sine wave voltage, with slow updates of about 2 samples per second. The bar graph keeps on displaying the TRMS voltage for that sine wave, instead of the peak voltage.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Robomeds on December 12, 2013, 06:23:55 pm
Still the cheapest option for a new sturdy 4 1/2 digit TRMS meter with autoranging. It is not a perfect meter by any means, but quite usable and probably the best value for a hobbyist on a budget.
Since you said "new" I would agree.  If you are willing to shop ebay and live in the US (one or both will be 'no' for many people) I think you can do much better.  For the same money I've seen these meters used, all of which strike me as better than the UNI-T
Amprobe AM140 (Brymen with 500,000 count display)
http://www.ebay.com/itm/Amprobe-AM-140-TRMS-Digital-Multimeter-With-Leads-WOW-NR-/161166659089?pt=LH_DefaultDomain_0&hash=item2586480e11 (http://www.ebay.com/itm/Amprobe-AM-140-TRMS-Digital-Multimeter-With-Leads-WOW-NR-/161166659089?pt=LH_DefaultDomain_0&hash=item2586480e11)
BK version of this meter (an ancestor of the current Agilent meters)  Note this is 40,000 count but has very good accuracy.
http://www.ebay.com/itm/Hioki-3801-Digital-HiTester-Multimeter-/290889897049?pt=LH_DefaultDomain_0&hash=item43ba639459 (http://www.ebay.com/itm/Hioki-3801-Digital-HiTester-Multimeter-/290889897049?pt=LH_DefaultDomain_0&hash=item43ba639459)
BK 5390 (a favorite of mine).  Rare on ebay but I got one for $35 and did a tear down of the meter.  0.025% DC, water proof (a need I haven't needed ;) ) and 50k count. 
A number of old bench meters. 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on December 24, 2013, 11:50:00 am
I just received my UT61E that I ordered when I saw that everyone is happy with it. And I like it!
Unfortunately I'm unable to use the data logging function using the serial cable and a USB to serial adapter. (http://dx.com/p/usb-to-rs232-dongle-with-extension-cable-5859 (http://dx.com/p/usb-to-rs232-dongle-with-extension-cable-5859))
The adapter is plug and play and I can see it linked to COM4 in "device manager". I installed UT61E v4.01 exe and connected to COM4 but I get nothing...

It's the first time I use RS232 so maybe I'm doing something wrong?

(http://farm4.staticflickr.com/3828/11529930096_3059cc693f.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Benik3 on December 24, 2013, 01:15:35 pm
Maybe different voltage output?
RS232 can be +-5V, +-10V, +-12V or +-15V.
Or there is also TTL +-3.3V but it's not probably this...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on December 24, 2013, 02:09:42 pm
Hum... I know absolutely nothing about RS232.  :palm:
I suppose that being powered by USB it can't be more than 5V. I looked at RS232 pinout and couldn't find a power pin!?
I checked all pin voltages on the USB to RS232 adapter and all are at 0V apparently. Is that normal?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on December 24, 2013, 03:28:47 pm
Make sure the infrared led actually works on the meter (use a digital camera or something which will show on the lcd the infrared). It should be fine.

Some of those cheap dongles use Prolific serial-to-usb chip CLONES ... the driver that windows loads detects they're clone chips or chips with the invalid prolific signature and will not work properly.

In your case, I would make sure the connectors are actually soldered properly on the pcb - the solder is often really bad on those.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Benik3 on December 24, 2013, 04:31:15 pm
It's strange that you didn't measured any voltage, because Logic 0 is high voltage, sou you should measure the max voltage at least on TX pin...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Nuno_pt on December 26, 2013, 04:09:09 pm
Hi,

Has anyone see or try this mod for adding new functions ( http://mjlorton.com/forum/index.php?topic=285.0 (http://mjlorton.com/forum/index.php?topic=285.0) ), and also this mod for external Vref from this Chinese forum ( http://forum.eepw.com.cn/thread/239953/1 (http://forum.eepw.com.cn/thread/239953/1) ).

On another topic ( https://www.eevblog.com/forum/testgear/ut61e-drift-and-recalibration/15/ (https://www.eevblog.com/forum/testgear/ut61e-drift-and-recalibration/15/) ) about the UT-61e stephenlm324 already did the external Vref mod along with replacing VR1 (2K pot) by 2 x resistors and 50Ohm pot and claims better accuracy and stability( page 2, post 18 ).

Amazing DMM.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on December 28, 2013, 01:56:57 pm
Make sure the infrared led actually works on the meter (use a digital camera or something which will show on the lcd the infrared). It should be fine.

Some of those cheap dongles use Prolific serial-to-usb chip CLONES ... the driver that windows loads detects they're clone chips or chips with the invalid prolific signature and will not work properly.

In your case, I would make sure the connectors are actually soldered properly on the pcb - the solder is often really bad on those.

Thanks for your reply. It took me a long time to test the DMM again as I was busy last week.

I checked that the IR led is working and it is blinking at about 2Hz. So I guess it works.

I tried different drivers but nothing seem to work...

I'm under Windows 7 64 bits and in device manager everything seems fine. The device is detected correctly and it created a virtual serial port (COM3). But when I try to connect to COM3 in the Uni-T software it does nothing. I also tried with UltraDMM but got the same results.

I'll now investigate the adapter itself to make sure there is no bad connection... But I'm quite desperate right now.

Thanks for your help!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on December 28, 2013, 03:24:44 pm
This is weird...
I got it to work, I don't know how. Then I restarted windows without touching the DMM or the serial adapter and now it doesn't work anymore.
This looks like it's either a bad solder joint (but I don't think so as I didn't touch anything) or a windows/driver problem.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Benik3 on December 28, 2013, 04:17:52 pm
Try to open the serial converter and looks what chip is inside and check soldering.

BTW does anyone know, what is inside the serial cable of the DDM?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Legit-Design on December 28, 2013, 05:26:13 pm
BTW does anyone know, what is inside the serial cable of the DDM?

Unitrend UT61E Ethernet Adapter with ATmega and ENC28J60 (https://www.youtube.com/watch?v=A8m_Os3OPhA#ws)
https://youtu.be/A8m_Os3OPhA?t=2m17s (https://youtu.be/A8m_Os3OPhA?t=2m17s)
2m17s starts about the adapter.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on December 28, 2013, 05:43:53 pm
I can't check what the chip of the USB to RS232 adapter is as it's below a black blob.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on December 28, 2013, 06:17:40 pm
This is driving me crazy! :S
I checked solder connections and all seem good.
Is it possible to get the chip ID in windows?
Title: Re: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on December 28, 2013, 06:42:54 pm
Try to open the serial converter and looks what chip is inside and check soldering.

BTW does anyone know, what is inside the serial cable of the DDM?
The schematic earlier in this thread has the schematic for the adapter I think.

Sent from my EVO using Tapatalk

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sachleen on December 28, 2013, 06:54:17 pm
It does, a HE2321U
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on December 29, 2013, 04:59:33 pm
I ran out of ideas regarding my problem with the RS232 adapter...
I'll give up for now unless you people have other ideas.

Thanks anyway for the help!  :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on December 31, 2013, 05:39:16 am

I ran out of ideas regarding my problem with the RS232 adapter...
I'll give up for now unless you people have other ideas.

Thanks anyway for the help!  :)

Lagman,

I suspect it is your RS232-USB convertor.  I had many problems with that when my UT61E was new.  The Rx light on the adaptor even blinks but the program doesn't read.  I tried a few different RS232-USB convertor and finally got a Sabrient with the FTDI chipset.  That cable was expensive ($17).

See this thread I wrote some time back:
https://www.eevblog.com/forum/testgear/ut-61e-rs232-usb-chipset-worked-and-chipset-that-failed/ (https://www.eevblog.com/forum/testgear/ut-61e-rs232-usb-chipset-worked-and-chipset-that-failed/)

Also, try to see first if the RS232 cable is working by connecting it to a "real" RS232 com port if you have an older machine with one.   This will rule out your UTE-to-RS232 part being the problem and we can focus on from RS232 to PC part.

Rick
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dr_p on January 06, 2014, 07:37:18 am
This is weird...
I got it to work, I don't know how. Then I restarted windows without touching the DMM or the serial adapter and now it doesn't work anymore.
This looks like it's either a bad solder joint (but I don't think so as I didn't touch anything) or a windows/driver problem.
I have major software problems in connecting a OBD scanner for my car. It's USB to Serial, and shows as a COMx in Device Manager, but doesn't really work. As it turns out, Toshiba Bluetooth Stack keeps screwing up the COM ports, somehow. I made it work at some point, but I don't remember how. I used it for some time, all was good, worked every single time. Lost it after a restart (weeks later, because the laptop always went into standby). It's frustrating because I can't remember what the flick I did.

I suspect you might have the same software issues.

I will dig more into how COM ports are managed on a modern PC and possible causes for other people's (unrelated) equipment not working on serial-over-USB.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on January 07, 2014, 09:21:59 am
Thanks for your reply. I'll take a look into other RS232 to USB converters.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on January 07, 2014, 02:20:13 pm
Bit of a sledgehalmmer approach is to install Virtualbox and the addons and let it handle the USB device. That way you can have very fine control as to which USB device is assigned and the driver it uses.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Dareksa on January 14, 2014, 09:34:37 am
Lagman, I have this kind of adapter http://allegro.pl/te7-adapter-usb-na-rs-232-com-pl-2303-prolific-i3876718203.html (http://allegro.pl/te7-adapter-usb-na-rs-232-com-pl-2303-prolific-i3876718203.html) and it working without problems with my UT61E.
You only have to set com port to port 1-3 in device manager.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on January 14, 2014, 11:58:13 am
Thanks for the link.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on January 14, 2014, 12:15:14 pm
Based on my experience, Prolific based converters could be problematic. FTDI based ones seem to be much less likely to have issues on most PC's, though more expensive.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lpc32 on January 14, 2014, 01:16:13 pm
There's also SiLabs. The CP2102 is common. Don't know how it is, but it costs closer to the Prolifics and I think all versions should have drivers for Windows 8.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Dareksa on January 14, 2014, 02:03:16 pm
You are right that the FTDI can be less problematic than other chips, but this Prolific converter works for me with each of my equipment.
Does not matter if I have to configure cisco switch, LPG in the car or connect UT61E to PC.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: uski on February 18, 2014, 01:03:29 am
Not sure if this has been posted already :
2500V vs a UT61E, guess who wins? Bonus: 5000V vs a Brymen BM869 (https://www.youtube.com/watch?v=hhBbvIf3E0s#ws)

Of course you don't have to work with 2500V to encounter such transient voltages.
Measuring the voltage across a relay coil might be enough if there is no free-wheel diode.
It can also happen with AC circuits if there is a motor, or in a car sometimes.

Any idea as to suitable MOVs or spark-gaps for a UT61E ?
Something that will allow 400VAC measurement safely but trigger at, say, 1000VAC ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on February 18, 2014, 06:21:32 pm
I added 2 275VAC VDR's in series in the 2 places on the PCB in mine. Works well enough to measure 250VAC, but will now clamp at 793V for overload. Just went and tested now with a high voltage source that goes to 1400V. The VDR's were the 5mm type from RS. I needed one, but the SSM is 5, so there were 4 spare and they were placed in the UT61E.

Bought both the UT61E and the Dy294 green lunchbox transistor/capacitor tester from Frankie ( Iloveelectronics).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on April 26, 2014, 05:55:01 pm
I haven't seen the Max Min modification done on the UT61E anywhere yet. So here it is:

Bridging pin 100 and 98 on the Cyrustek IC will disable the REL mode and enable the Max/Min mode, which I find more useful.
Be careful with the soldering, as the pins are very close to each other. It isn't necessary to cut any traces and the mod is reversible at any time.
Max Min works with most meter selections.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on May 20, 2014, 05:31:09 pm
I'm trying to measure the frequency and duty cycle of a flashlight which uses PWM to control light intensity.
I set my DMM using the 10A slot  on the A range:
(http://img4.hostingpics.net/pics/683996IMG1700.jpg)
And put the meter in series (like I would do to measure the amp draw).
I get no readings either for duty cycle or frequency.
Am I doing something wrong? Thanks.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on May 20, 2014, 05:44:05 pm
Of course you're doing something wrong. The meter only measures current when you use the 10A jack.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on May 20, 2014, 06:06:49 pm
In that case why is there a yellow symbol "Hz" under the A range?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on May 20, 2014, 06:15:42 pm
Try the 10A AC selection. If that doesn't work, try the AC mA position, if the current is below 220mA.
The AC voltage selection should also give you frequency and duty cycle.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on May 20, 2014, 06:31:24 pm
The light uses about 2A. I tried the 10A AC but no success.
(http://img15.hostingpics.net/pics/963569IMG1702.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on May 20, 2014, 07:59:03 pm
This is really strange. I'm wondering if I'm doing something wrong...
Is there somebody out there with a UT-61E who could test this?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on May 20, 2014, 08:24:37 pm
HKJ gave me the answer.
http://budgetlightforum.com/node/8642?page=2#comment-585893 (http://budgetlightforum.com/node/8642?page=2#comment-585893)
Seems like even though you can display Hz in DC Amp range the meter needs AC.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on May 21, 2014, 06:22:56 am
The book says no DC offset allowed when measuring frequency:
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: HKJ on May 21, 2014, 06:26:10 am
The book says no DC offset allowed when measuring frequency:

That table is for the frequency (Hz) position. In the above case frequency was measured on the current input, with DC selected.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on May 21, 2014, 07:25:09 am
No, that note covers all frequency selections.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: HKJ on May 21, 2014, 07:35:19 am
No, that note covers all frequency selections.

Not as it stands, the frequency is only up to 1kHz when measuring it in the current ranges.
The note "DC electric level is zero" must mean that it only works for AC, not pulsing DC. In the "fast" test I made it was not critical with DC offset, but it needed something below zero to work.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on May 21, 2014, 11:12:52 am
An other thought:
The manual says:
***
5. Press Hz% to obtain the frequency and duty cycle value.
   Input Amplitude: (DC electric level is zero)
   Input Amplitude:    >rangex30%
   Frequency response:UT61A and B <400Hz
                UT61C , UT61D andUT61E   <1KHz
***
I set the meter to the 10A range. Maybe that my input amplitude needs to be at least 3A (30%) in order to get a reading?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: multiJ on May 22, 2014, 09:28:00 am
Hello all. Is this DMM still good value for a hobbyist at the $50 range, please (mainly for small battery testing and light electronics work). Thank you  :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: HKJ on May 22, 2014, 09:31:37 am
Hello all. Is this DMM still good value for a hobbyist at the $50 range, please (mainly for small battery testing and light electronics work). Thank you  :)

I believe it is, but watch out for the current ranges, the burden voltage is a bit high in some cases.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: multiJ on May 22, 2014, 09:49:09 am
Thank you HKJ. I was wondering if the UT61E is decent for this kind of work:
http://www.lygte-info.dk/info/Measurement%20UK.html (http://www.lygte-info.dk/info/Measurement%20UK.html)


(edit for spelling)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: HKJ on May 22, 2014, 09:56:45 am
Thank you HKL. I was wondering if the UT61E is decent for this kind of work:
http://www.lygte-info.dk/info/Measurement%20UK.html (http://www.lygte-info.dk/info/Measurement%20UK.html)

It is, except for some measurements in mA and uA range, where the burden voltage is to high (Using an external resistor can fix that).
The problem ranges are 2200uA and 220mA, i.e. between 0 and 200uA it has very low voltage drop, same with 0 to 20 mA range.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: multiJ on May 22, 2014, 10:22:26 am
That is very helpful, much appreciated
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on August 01, 2014, 04:24:51 pm
Brand new UT61E, bought on ebay, shipped directly from Shenzen. Markings on  PCB: 150507-9 61E

When measuring clear DC on voltages above about 8 volts, I get this erratic readings on AC range, goes OL and back with beeping when OL is displayed. I have no idea what the problem is. Sorry no sound this is the only camera I got.


https://www.youtube.com/watch?v=9DcmOKxp2Eo&feature=youtu.be (https://www.youtube.com/watch?v=9DcmOKxp2Eo&feature=youtu.be)


http://postimg.org/image/o3whew8vf/ (http://postimg.org/image/o3whew8vf/)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on August 01, 2014, 04:49:20 pm
It's normal, the meter is not designed to measure AC voltage when there's DC voltage present as well.

This, plus the rare incorrect display for one reading when it changes ranges are the only "major" issues this multimeter has. The high burden voltage on some ranges (as explained above) I consider minor issue, easily to work around.



Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on August 01, 2014, 05:07:36 pm
It's normal, the meter is not designed to measure AC voltage when there's DC voltage present as well.

This, plus the rare incorrect display for one reading when it changes ranges are the only "major" issues this multimeter has. The high burden voltage on some ranges (as explained above) I consider minor issue, easily to work around.

I had one bought 2 years ago that was in the same circumstances reading O an AC, wasn't jumping as this one. Can't remember what revision PCB was.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on August 16, 2014, 03:53:15 pm
My 6F22 9V battery just died, 6 months after buying the meter (I use it a lot).
What is the best battery in this format? I saw http://www.fasttech.com/products/1046603 (http://www.fasttech.com/products/1046603) which is cheap.
I also saw http://www.fasttech.com/products/0/10002905/1812000-soshine-650mah-9v-li-ion-rechargeable-battery (http://www.fasttech.com/products/0/10002905/1812000-soshine-650mah-9v-li-ion-rechargeable-battery) which is more expensive but might be a better deal in the long run?
Funny thing is that my smoke detector started beeping a few days ago even though the battery still shows 9.1V open circuit. (Bad design?)
I think I'll use new batteries in the smoke detector and then place them in the multimeter...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Monkeh on August 16, 2014, 03:56:18 pm
If you put a lithium primary cell in you'll probably need a new meter before you need a new battery.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on August 16, 2014, 04:17:09 pm
Thanks!
Locally I'll have a hard time finding a 9V lithium primary... Do you know an online store where I could buy it?
EDIT: I found some on amazon but they are 8-12 euros a piece (11-16USD) :/
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lagman on August 16, 2014, 04:37:22 pm
Is this a good idea?
http://www.aliexpress.com/item/1200mAh-Smoke-Alarm-9V-Lithium-Battery-ER9V/1985926539.html (http://www.aliexpress.com/item/1200mAh-Smoke-Alarm-9V-Lithium-Battery-ER9V/1985926539.html)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on August 16, 2014, 04:46:47 pm
Lithium > Alkaline > heavy duty 

Get alkaline, best value for money. Lithium will last longer, but probably not as much as 4-6 alkaline batteries that will cost the same (if you make the total).

Also note that the low battery voltage on ut61e shows up at about 5.5v but the meter itself can operate just fine even under 3v, so the batteries you take out of your meter may still work for a few hours to run a clock or something using very low power, with the 5-5.5v the battery has left.

Lithium 9v batteries  start at about 8.4v and they're completely dead at about 5.4v so you would get almost all of their energy before the meter says low voltage.

For example, you can see in this datasheet http://data.energizer.com/PDFs/la522.pdf (http://data.energizer.com/PDFs/la522.pdf)  that with 5mA draw (a bit more than what UT61E draws) the battery will last about 800 hours.

To compare, you have here an alkaline battery datasheet: http://data.energizer.com/PDFs/522.pdf (http://data.energizer.com/PDFs/522.pdf)  on page 2 you can see that with about 10mA draw, the battery will go down to about 6v in around 70 hours. So you can extrapolate about 150 hours at 5mA and down to 5.5v...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Legit-Design on August 16, 2014, 04:49:27 pm
Thanks!
Locally I'll have a hard time finding a 9V lithium primary... Do you know an online store where I could buy it?
EDIT: I found some on amazon but they are 8-12 euros a piece (11-16USD) :/
Yes, good quality lithium primary batteries cost money. If you don't pay for good quality you might get crap, if you don't get crap you got lucky.
Is this a good idea?
http://www.aliexpress.com/item/1200mAh-Smoke-Alarm-9V-Lithium-Battery-ER9V/1985926539.html (http://www.aliexpress.com/item/1200mAh-Smoke-Alarm-9V-Lithium-Battery-ER9V/1985926539.html)
Most likely you will get old stock that is already partially discharged or maybe even faulty, order at your own risk.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mikeva on October 29, 2014, 06:58:04 pm
Hi guys,
I just bought the UNI-T 61E  and i have to say... it's awesome for the price .I know that it's not for measurements  phase to phase etc...
But please answer me this:
Is it safe to use it measuring dc voltage on a tube amplifier?I'm talking about 400-500VDC maximum.
What about ac voltage?380 VAC Is it too much?

can anyone please  answer me this?Thanks for your time!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on October 29, 2014, 07:03:26 pm
I would use it for a PS for a tube amp.

Its is also probably OK for 380VAC and you most likely won't have a problem. The thing is that you never know when there will be a problem on the line, like a spike, that could kill the meter or injure you. Personally I would avoid using it for that use, but you will almost always have no problem. It is the infrequent occurrence that hurts or kills someone that causes meters to need the safety ratings that we have now.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: HKJ on October 29, 2014, 07:22:18 pm
There are generally two safety problems with DMM.

One is measuring voltage in high current circuits with probes connected to the current terminal on the DMM. If the DMM is without fuse or a "cheap" fuse it may not be able to break the current and will explode.

The other is spikes. There is a risk for high voltage spikes on the mains. This can lead to arcs inside the DMM and again you risk explosion.

The above is usual not a problem behind a small transformer.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mikeva on October 30, 2014, 07:30:30 am
Thanks for the reply guys!
Well that make sense....I'll give it a chance.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: v3n0m3n0 on November 08, 2014, 10:02:26 am
Hi guys ! 

Just bought new UNI - T 61E on ebay, after a closer look I found out that my unit has different PCB layout compare to this what I've seen before. 

What do you think,  improved construction will help to pass the European safety tests as CAT III 1000V multimeter ?

(http://i57.tinypic.com/2u5t175.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on November 08, 2014, 10:22:52 am
Although it has an extra PTC and some beefier diodes on the mA protection circuit, it still uses the same BS1362 250V fuses. Just on the strength of that, it doesn't meet the latest IEC CAT 1000V regulations.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on December 11, 2014, 06:48:09 pm
I wonder will this improved protection version survive the 2500V test.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on December 11, 2014, 10:06:18 pm
Probably not. The extra PTC won't stop a high voltage from passing through. It needs the missing spark gaps or MOVs.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: squeck on December 22, 2014, 11:38:34 am
Hello guys, I'm new to the forums and I received my UT61E today.

Is it normal that is reads around 300nF when in capacitance mode even if the leads are not connected to anything?

Thanks
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Maxlor on December 22, 2014, 07:07:45 pm
300nF is enormous. Mine reads about 0.060nF without the leads, and 0.080nF with the leads connected. I hear that the new PCB revision has a higher inherent capacitance of about 0.300nF. Are you sure you haven't overlooked the decimal point?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: squeck on December 22, 2014, 07:15:21 pm
300nF is enormous. Mine reads about 0.060nF without the leads, and 0.080nF with the leads connected. I hear that the new PCB revision has a higher inherent capacitance of about 0.300nF. Are you sure you haven't overlooked the decimal point?

Oh man, I miswrote it!

What I meant was 0.300nF (actually, it's ~250nF without the leads) so I assume it's correct and I have the new PCB revision.

Thank you for your reply :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mad Mart on December 22, 2014, 07:16:49 pm
Mine also reads 0.060nF without the leads & 0.078 with.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Guni on December 29, 2014, 11:01:56 pm
My UT61E has another variant of PCB layout compare to few previous. Inside label: 25-Jul-14
I bought it from official European distributor. Quality is OK except terrible probes, I have much, much better with my old and very good, cheep Metex 68. 

(http://i62.tinypic.com/2qn9s7p.jpg)


Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: WackyGerman on January 02, 2015, 12:45:57 pm
This multimeter never ever would meet the regulations for cat 3 300V and cat 2 600V because the fuses are BS1362 250V rated . In the newest regulation all ranges has to meet the ratings and not only the voltage ranges . By the way , if you see the video from Dave how a good serious input protection is built and work and you compare it to this multimeter so your result is that this meter has not an input protection that will work  and it never never never would survive and protect the user from injuries . Here in Germany this meter cost roundabout 90 € and it s definively not worth . No input protection , crappy BS 1362 fuses and the input jacks are horrible as well . There are much better multimeters available in this price range , for example the Brymen BM257 at tme for roundabout the same price
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Guni on January 02, 2015, 01:32:29 pm
There are much better multimeters available in this price range , for example the Brymen BM257 at tme for roundabout the same price
It's not exactly true, UT61E is 1/3 cheaper then BM257 and it's widely available.
For many people IEC CAT 1000V regulation is not so important because they operate on low voltage.
From other hand there is not any other option with 22000 count resolution in this price range.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on January 02, 2015, 08:08:54 pm
Yes, the Brymen BM257S is not even close to the same price. IMHO if you do not need the PC connection then the UT139C is a much better meter for the same or less money.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: crystal on January 02, 2015, 11:10:41 pm
My UT61E has another variant of PCB layout compare to few previous. Inside label: 25-Jul-14
I bought it from official European distributor. Quality is OK except terrible probes, I have much, much better with my old and very good, cheep Metex 68. 



Trust me once you clean the probes from residue they are actually very good quality just 0.05 ohms per probe, extremely sharp made for electronics. With all it's flaws UT61E is still the best buck for the money for electronics and if you are going for something better it will cost you about +100$ and it will still not be perfect.
And don't buy from local distributors in your country that ramp up the prices, buy it from ebay, it's currently just 48$. It's an extremely good value for the money.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: centaurian on January 03, 2015, 10:34:11 am
Hi guys ! 

Just bought new UNI - T 61E on ebay, after a closer look I found out that my unit has different PCB layout compare to this what I've seen before. 

What do you think,  improved construction will help to pass the European safety tests as CAT III 1000V multimeter ?

(http://i57.tinypic.com/2u5t175.jpg)


I'm missing something, or there aren't reserved spots for GDTs on pcb anymore?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on January 03, 2015, 10:45:44 am
3 blank spots on the PCB next to the PTC thermistors for them. If you put in the small GDT or MOV units it will improve things, though it still will not really be suitable for high energy high voltage use.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: WackyGerman on January 03, 2015, 01:06:43 pm
Well the price here in the EU for the UT61E ist about 80 Euro at Ebay also . 48 $ in the US is a real big difference and for this multimeter it is a fair price . In Europe the price level for testing equipment is really high  :bullshit:
22000 counts is a real good resolution for this price range I must confess . Might be handy for look for relative changes at charging or discharging or something like that . 6000 counts of the BM257 is far away from that . Now the price for the brymen at tme is 81,30 € plus VAT 19% = 96,75 € . The difference is roundabout 20 % here in Europe .
For low energy measurements the UT61E is ok and 48 $ is a good value for this meter . But 80 € is a rip off . Well for comparison Greenlee also sells the BM 257 badged to Greenlee DM510-A and the shocking price is 202 € here in Europe  :scared: :scared:

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: crystal on January 03, 2015, 01:44:55 pm
48$ is all over the world. I don't get it why would you buy it from 2X more expensive ebay.de when it is much cheaper on .com.

There is nothing in the EU law that obligates you to buy strictly from ebay.de. The meter is safe enough and is allowed to be sold in EU.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on January 03, 2015, 02:08:37 pm
Actually if I understand things correctly, the GS version is sold in Germany and it has a different design. The GS version has better input protection but has a lower CAT rating. The information is here on the forum somewhere and in this thread I think.

After having both the UT61E and the UT139C I recommend the UT139C instead, if you don't need the PC connection.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: WackyGerman on January 03, 2015, 02:34:56 pm
Well I looked at ebay.com and the best price for the UT61E is 40 $ + 8,19 $ shipping cost at a dealer from Hongkong / China . But seriously , do you can guarantee that it is genuine  ( Chinese also counterfeit chinese products  ;) ) or meet their specifications ( it s cheaper to sell this crap than to destroy it  >:D ) . The business is hard and merciless , also in china and nobody has anything to give away . So I would be really careful with this offerings even these are really tempting offers for you .
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: torr032 on January 03, 2015, 03:07:21 pm
WackyGerman you are really one hella of a wacky man :)

Trust me the meter is allready a bargain with its price, it's just 35$ in China. They don't copy these cheap products and especially their own, it is perfectly safe to buy it directly from Shenzhen where it is manufactured.

If you need it for electronics, definitely buy UT61E. If you need for electrical works consider buying UT139C.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: WackyGerman on January 03, 2015, 04:23:09 pm
Actually if I understand things correctly, the GS version is sold in Germany and it has a different design. The GS version has better input protection but has a lower CAT rating. The information is here on the forum somewhere and in this thread I think.

After having both the UT61E and the UT139C I recommend the UT139C instead, if you don't need the PC connection.

OK maybe there are really some different versions on the market with different certifications and cat ratings . Maybe this would be the reason of the price here in Europe . They let pay the GS certification by the german customers for lowering the cat ratings . Crazy business  :-DD
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on January 03, 2015, 04:33:40 pm
The GS version just is a more honest rating for the meter. The non GS version is somewhat optimistic in it's rating for overload, and the meter is not likely to survive testing to the standard without damage. The GS version will probably survive the testing without major malfunction.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Didix on January 04, 2015, 05:03:11 am
As much as I can see from the offers on Alibaba, the Chinese ones come with a serial interface
whereas the ones in Germany come with the USB interface which would cost an extra around US$ 15 for the Alibaba one.

After having both the UT61E and the UT139C I recommend the UT139C instead, if you don't need the PC connection.

I have made a lot of reading in that thread,
but I am not yet sure whether my additional DMM will be a UT61E or UT139C.

If we neglect the fact of the price difference and
the fact that I am working on voltages below 230V and
did never use temperature measurement with my UT70A,
would you (or others) still go for the UT139C?

If yes, why?

-Didix
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on January 04, 2015, 05:06:43 am
If we forget the benefits of the U139C what is the benefit of a UT139C?  :wtf:  |O

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: DaJones on January 04, 2015, 05:48:01 am
Quote
If we neglect the fact of the price difference and
the fact that I am working on voltages below 230V and
did never use temperature measurement with my UT70A,
would you (or others) still go for the UT139C?

If yes, why?

I think that is a very valid question.

I, too, do not need the high voltage protection or computer communications. I will be working with low voltages on my bench.

FROM THAT PERSPECTIVE ( not shouting, just emphasizing ), I would be very interested in hearing what everyone thinks.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Ether on January 04, 2015, 07:41:13 am
Geez, I think this debate has been around for a pretty long time. You could probably check out the UT139C thread for more info.

In short, UT139C = better protection, temp. , larger digits (no bar graph), backlight, NCV, VFC, faster update speed.

UT61E= higher count, bar graph, pc connection
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Didix on January 04, 2015, 08:24:42 am
Did anybody connect two UT61E via the USB Connector to the same computer?
Will this work?

-Didix
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: crystal on January 04, 2015, 12:01:05 pm
As much as I can see from the offers on Alibaba, the Chinese ones come with a serial interface
whereas the ones in Germany come with the USB interface which would cost an extra around US$ 15 for the Alibaba one.

After having both the UT61E and the UT139C I recommend the UT139C instead, if you don't need the PC connection.

I have made a lot of reading in that thread,
but I am not yet sure whether my additional DMM will be a UT61E or UT139C.


If we neglect the fact of the price difference and
the fact that I am working on voltages below 230V and
did never use temperature measurement with my UT70A,
would you (or others) still go for the UT139C?

If yes, why?

-Didix

Buy the one that will fill up the cons of the multimeter you already have so they can supplement each other. What is your first multimeter?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Yago on January 04, 2015, 12:28:07 pm

If we neglect the fact of the price difference and
the fact that I am working on voltages below 230V and
did never use temperature measurement with my UT70A,
would you (or others) still go for the UT139C?

If yes, why?

-Didix

How do you know you will be working on voltages below 230?
The point with a meter is that you measure things with unknown values.

I was checking through television and ethernet cables in my house, had moved the rooms around and one PC/tv wasn't working correctly.
After a bit of headscratching, thought I'd better bell out these leads.
All the ethernet was belling out to televison and PC, and nothing would work properly...arg.
A thought that the TV wire has a long run and could have picked up some noise or damage to the cable and that too should be tested.
Display on the meter flashed!! WTF volts on the TV cable!!!

Turned the meter over to Volts stetting, checked and the meter display flashed again.

Putting it simply, whatever was on that TV aerial wire is more than the max volt capability of a CATIII 1000v Brymen 857s.

I have no equipment and no supplies of such voltage but it is here in my home.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on January 04, 2015, 01:41:36 pm
Congrats, you have a floating antenna lead, picking up static charge from the air and feeding it down the lead.  Roof antenna will need an earthing lead leading straight down from it to a 1.5m long earth spike driven into the earth directly underneath it. That should get the voltage down to a low level. Use 2.5mm cable ( rated for 20A) and coat the join to the copper coated steel earth rod with dielectric grease to keep corrosion at bay. If it already has an earth rod it is likely it has rusted away in the ground, pound in a new one next to it and join to the grounding wire.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Yago on January 04, 2015, 02:07:25 pm
Congrats, you have a floating antenna lead, picking up static charge from the air and feeding it down the lead.  Roof antenna will need an earthing lead leading straight down from it to a 1.5m long earth spike driven into the earth directly underneath it. That should get the voltage down to a low level. Use 2.5mm cable ( rated for 20A) and coat the join to the copper coated steel earth rod with dielectric grease to keep corrosion at bay. If it already has an earth rod it is likely it has rusted away in the ground, pound in a new one next to it and join to the grounding wire.

Hmm, it was connected to a lot tv stuff: distribution amp, dvd, cable tv...much of that earthed.

Still haven't had time to work out what the source was, just disconnected and isolated everything I could.
Will post back what I find, I don't think it is safe to assume it's static.
Would static hold a multimeter in clamped overvolt warning mode?
Thought it would dissipate pretty quick.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on January 04, 2015, 02:22:56 pm
Depends where you are, you can have a quite high power developed on a floating system, though as you say there is a lot of cable and such stuff, which likely is floating and is capable of withstanding 2kV WRT ground.

Short it to a good ground and see if it is AC or DC current that flows. Probably best to use a 10A range on a meter just in case, and a meter you are happy to make an oops with as well.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Yago on January 04, 2015, 02:27:34 pm
Cheers Sean.
Will have a look this week and post findings.

Hmm,  an old Avo might be getting a dusting off!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on January 04, 2015, 02:31:28 pm
If you are only going to use the UT61E on the bench and not care if you have NVC, temperature, back light, safe input protection, faster and bigger digits, then the U61E is a better buy. These are the benefits of the UT139C. If you take the benefits away, the reason to buy anything go away, thus my  ":wtf: |O"

The UT61E has three benefits only IMHO. #1 higher count, #2 higher accuracy, #3 PC connection included. Of those three the only thing of real importance for the common user is the PC connection which is rarely used anyway. The UT139C is a better buy because of the things I listed. The proper input protection and NCV detector means that you don't have to guess if you are using the meter on a high voltage/energy circuit because it is protected correctly and you can see if there is a live circuit before touching it. The UT139C is more versatile and therefore a better buy "if you don't need the PC connection", as I said.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: gocemk on January 04, 2015, 02:36:42 pm
Quote
If we neglect the fact of the price difference and
the fact that I am working on voltages below 230V and
did never use temperature measurement with my UT70A,
would you (or others) still go for the UT139C?

If yes, why?

-Didix

Hi, since i own the both multimeters, here's my 2 cents:
The UT61E feels much more responsive, the autoranging speed is faster than the UT139C, especially for measuring resistance. The continuity tester is also slightly faster on the UT61E. If you ever need data logging capabilities (i do) the UT61E comes in really handy. I have used this multimeter with voltages up to 220 V AC while doing some basic electrical maintenance without a problem. On the other hand, the UT139C has better input protection, backlight, temperature measuremenr (only 1 degree resolution), NCV, low pass filter, and current clamp capability (up to 60A) which comes in handy while doing electrical work. I use this meter mainly while i am on field work working on automation equipment and cabinets. Having said all that, the UT61E is better suited in lab environments working with "low voltage" electronics e.g. MCU's, PLC's or other types of digital control (or similar) ELECTRONICS, while the UT139C is better suited for ELECTRICAL work. If the missing data logger and the slightly slower autoranging of the UT139C are not a deal breaker for you, go for that one. Both meters are great value for money so you won't make a mistake with either of them.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Didix on January 04, 2015, 03:00:18 pm
Thank you guys

I think I will go for the UT61E.

As some of you are guessing right: I will primarily be using it on the bench!

For higher voltages and 'unknown' experiments I got my Fluke 76.
For temperature measurement my UT70A.

The UT61E feels much more responsive, the autoranging speed is faster than the UT139C, especially for measuring resistance. The continuity tester is also slightly faster on the UT61E. If you ever need data logging capabilities (i do) the UT61E comes in really handy.
...
 the UT61E is better suited in lab environments working with "low voltage" electronics e.g. MCU's, PLC's or other types of digital control (or similar) ELECTRONICS, while the UT139C is better suited for ELECTRICAL work.

If you are only going to use the UT61E on the bench and not care if you have NVC, temperature, back light, safe input protection, faster ad bigger digits, then the U61E s a better buy.
...
The UT61E has three benefits only IMHO. #1 higher count, #2 higher accuracy, #3 PC connection included. Of those three the only thing of real importance for the common user is the PC connection which is rarely used anyway.

What I actually could use is a second Logger.

Therefore my unfortunately not yet answered question:

Did anybody connect two UT61E via the USB Connector to the same computer?
Will this work?

I would be happy, if somebody has tried this out before ..

Well, actually I could buy the second UT61E with a serial interface.
Did somebody try that case? (one connected with USB and the other witch RS232 to the same computer)

-Didix
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Thilo78 on January 04, 2015, 03:13:00 pm

I would be happy, if somebody has tried this out before ..

Well, actually I could buy the second UT61E with a serial interface.
Did somebody try that case? (one connected with USB and the other witch RS232 to the same computer)

-Didix

Hi Didix,

can't tell for the UT61E, but I just tried with my UT71E, both connected via USB.

I just opened the software twice and was able to display both meters (see screenshot).
Second window comes up with an error, but it doesn't seem to matter.

Hope it helps

Thilo

edit: Remark: Just a very, very quick test.  :-DMM
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: crystal on January 04, 2015, 03:20:22 pm
I wonder does this latest UT61E pcb version overshoot when meausuring volts. Usually meters with weak input protection overshoots, so this latest version with improved protection should perform better.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Didix on January 04, 2015, 03:57:55 pm
Hi Didix,

can't tell for the UT61E, but I just tried with my UT71E, both connected via USB.

I just opened the software twice and was able to display both meters (see screenshot).
Second window comes up with an error, but it doesn't seem to matter.

Hope it helps

Thilo

edit: Remark: Just a very, very quick test.  :-DMM

Thanx so far Thilo!

Yes, the software can start up twice.
And it tells us, that the DB File is locked.

What we cannot see from your test is whether it is able to acquire and save two different signals at the same time.
And whether this data go to the same database or whether they can be saved to two files.
Would be perfect, if you (or somebody else) could give it a try  ::)

-Didix
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on January 04, 2015, 04:05:56 pm
Try installing the software twice to two different directories perhaps. Might not be possible.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Thilo78 on January 04, 2015, 04:09:56 pm
Yep, I see the problem now.
Actually, when leaving the meters and the two software instances on for a few minutes, one windows ceased to work.

Apparently working with two windows is not actually working.  :-//

Would have been too easy, I guess.
Also selecting the COM ports doesn't change anything...

The DB seems to be the same. I can't change it in preferences or whatever.

Edit: Tried the "two directories" method. This solves the DB issue.
But the problem is: The software doesn't check for individual USB ports. Thus one DMM wins, the other is not recorded  :-\
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on January 04, 2015, 05:05:21 pm
Check this thread:

https://www.eevblog.com/forum/testgear/uni-t-ut71d-review/msg442169/#msg442169 (https://www.eevblog.com/forum/testgear/uni-t-ut71d-review/msg442169/#msg442169)

(https://www.eevblog.com/forum/testgear/uni-t-ut71d-review/?action=dlattach;attach=93268;image)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Didix on January 04, 2015, 07:57:56 pm
Check this thread:

https://www.eevblog.com/forum/testgear/uni-t-ut71d-review/msg442169/#msg442169 (https://www.eevblog.com/forum/testgear/uni-t-ut71d-review/msg442169/#msg442169)

Hi Wytnucls

thanx for that hint - very good review!
I have read the whole thread.
I think what you are referring is the sentence
  "Multiple meter logging is possible, in two separate windows."
This sounds good news!

However, Thilo reports that it freezes after a couple of minutes.

Did you run it for a longer period of time and were you able to save two sets of data?

What did you do to get it reliably running?

-Didix
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Thilo78 on January 04, 2015, 08:04:44 pm
And most important:
When trying, I couldn't get the second meter to appear in that second window...
How did you hook up the USB cables? To individual ports on the laptop, or a hub? (can't recognize that from the pic)  :-//

Thilo
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on January 05, 2015, 01:35:41 am
I have 2 USB cables that came with the 71B and 71D. One is marked USB in white font, the other is also marked USB, but in raised font.
The 61E logging only works with the USB in white font cable. The 61E doesn't log in tandem with any of the 71 meters.
The 71B and 71D can log together easily for as long as required (using their own dedicated software), the 71B using the raised font cable and the 71D the other one.
Both sets of data are saved on 2 separate Excel files.
No hub is used, just any of the 3 USB ports on a Sony VPCZ1, running Windows 7.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Didix on January 05, 2015, 06:50:00 pm
@Thilo:

Which version of the UT61E software did you try: v2 or v4?

Did you already try DMM (https://www-user.tu-chemnitz.de/~heha/hs/UNI-T/ )?
From the infos on that page it is not clear whether you can log two UT61E or not.

-Didix
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Thilo78 on January 05, 2015, 06:59:25 pm
@Thilo:

Which version of the UT61E software did you try: v2 or v4?

Did you already try DMM (https://www-user.tu-chemnitz.de/~heha/hs/UNI-T/ )?
From the infos on that page it is not clear whether you can log two UT61E or not.

-Didix

*UT71E  ;)
I have two identical (with succeeding serial numbers, so same batch I suppose) UT71E, directly bought in China.

First, I used the software, which I downloaded earlier. It's v2.00, IIRC.
Second go, I used the current software v3.00.

edit: Both ways didn't work.
I'll have to check with my laptop, using USB ports without a hub.
Maybe tomorrow or next weekend, as I'll be away in between.

I didn't yet try the DMM software you linked.
I'll check it a.s.a.p.  :-+
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Didix on January 05, 2015, 07:35:21 pm
Yes, sorry, I have overseen that you have two UT71E.

I ask myself, whether it matters, what software you take. They look all the same and DMM seems to talk to all Uni-Ts.

However, to put the question again into the ring: does anybody have two UT61E?

I'll never give up!  8)

-Didix
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Thilo78 on January 05, 2015, 07:47:22 pm
I'm not perfectly sure, if the type matters if both meters are the same.
But it occurred to me, that it works if you have two different meters. Maybe the USB identifier is different between UT71E and UT71D or other combination....    :-//

Let me try, if I can manage to hook up the two UT71E by using direct USB connection.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: crystal on January 05, 2015, 08:00:00 pm
Actually if I understand things correctly, the GS version is sold in Germany and it has a different design. The GS version has better input protection but has a lower CAT rating. The information is here on the forum somewhere and in this thread I think.

After having both the UT61E and the UT139C I recommend the UT139C instead, if you don't need the PC connection.

OK maybe there are really some different versions on the market with different certifications and cat ratings . Maybe this would be the reason of the price here in Europe . They let pay the GS certification by the german customers for lowering the cat ratings . Crazy business  :-DD

This is the German GS version:
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: centaurian on January 05, 2015, 11:44:30 pm
crystal: Interesting. So it differs from Chinese version with 4 MOVs and bigger fuse holders - https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/msg545943/#msg545943 (https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/msg545943/#msg545943) (Also, there is missing VR5 calibration resistor for 10A range on that GS version).

So what's fuse voltage rating and type of MOV used in GS version?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Didix on January 06, 2015, 04:40:37 pm
Did you already try DMM (https://www-user.tu-chemnitz.de/~heha/hs/UNI-T/ )?

I have been talking to the author of DMM.
This seems to be our program  :-+

You should be able to start two instances and connect two DMMs and each instance catches a DMM.
Each instance should then write its own logfile.

However, you will not get a single logfile with synched data. You have to do the sync after logging.
Well, that's ok for me.

Would be nice if somebody who owns two UT61E with USB interfaces could make a test  ::)

-Didix




Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Thilo78 on January 06, 2015, 05:42:00 pm
[...]
Would be nice if somebody who owns two UT61E with USB interfaces could make a test  ::)

-Didix

Basic test with 2 UT71E: Works.

After startup of each instance, you can select between USB1 and USB2, and then display the data from the meter.
From the window you can select "Log to file" and then define a log file name for each window.

Trap for young players: Don't forget to activate "Send" on the UTs. Otherwise you might curse and search for a minute or so  :palm:

Nice tool. Not beautiful, but it does its job.

btw: Tried the same with the UNI-T software v3.00, but with the original USB ports of my laptop:
Actually it works with two instances, but if you open the second window, both will log data from the same unit  :-DD
Apparently, it's not intended to be used with identical meters...

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Didix on January 06, 2015, 07:04:29 pm
Perfect!

Looks that I need to order one more ...

Thanx fo testing !!

-Didix
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Thilo78 on January 06, 2015, 07:52:49 pm
You're welcome!
Gern geschehen!  :-+

I knew having two UTs might come handy one day  :-DD

Another question:
Just took one of the UT71E apart. Although they are original Chinese, non-export versions, the PCB seems to be ready for upgrade with HRC fuses and additional MOVs (one is present, the other spots are unpopulated). I just can't recognize if the MOV spots have traces to them...

Is it worth to take care of these parts as a weekend project?  :-/O
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on January 07, 2015, 05:27:13 am
Did you already try DMM (https://www-user.tu-chemnitz.de/~heha/hs/UNI-T/ )?

I have been talking to the author of DMM.
This seems to be our program  :-+

You should be able to start two instances and connect two DMMs and each instance catches a DMM.
Each instance should then write its own logfile.

However, you will not get a single logfile with synched data. You have to do the sync after logging.
Well, that's ok for me.

Would be nice if somebody who owns two UT61E with USB interfaces could make a test  ::)

-Didix

I don't have two UT61E, but I often connect my UT61E along with other devices also connected to the PC.

If all else failed....

The UT61E sends out data in standard 7 bit ASCII.  (8 bit word but MSB is always zero).  A TTY terminal emulation program will capture it nicely (and save/log to file.)  So you can just start multiple instances of something like Hyperterminal and log the lines to file.

While it is feasible to capture different devices to different text files, it gets a little messy when the lines are not individually time stamp-ed.  So, I found it easier to just write a Java program to grab the data from different ports (different devices) and log it to single file with PC's time stamp.   I suppose you can write one with BASIC as well.  My version of Basic supports only COM1 & COM2, so JAVA for me is easier and can use any COM port.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: crystal on January 08, 2015, 07:08:55 pm
crystal: Interesting. So it differs from Chinese version with 4 MOVs and bigger fuse holders - https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/msg545943/#msg545943 (https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/msg545943/#msg545943) (Also, there is missing VR5 calibration resistor for 10A range on that GS version).

So what's fuse voltage rating and type of MOV used in GS version?

The pic is from another thread, it seems I just can't find it now. I think I read somewhere fuses are 600V rated. Greetings
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mikeva on January 10, 2015, 10:02:31 pm
hi guys!
it's been 2+ months since i bought the 61E and everything was ok until today....
I had an old transformer that i wanted to measure and wanted to figure out  which pins are for the primary 220v and which are  for the secondary 12v. Unfortunately by my mistake  i plugged the transformer giving the 220v on to the secondary and the result was to blow the multimeter.Didn't understand why that happen despite that the scale was on the ac volts as it should.....Now it's dead.Won't turn on.The fuses are ok,the ptc's seems ok ,the rectifier diode also ok.Any ideas?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Maxlor on January 10, 2015, 10:18:34 pm
Not exactly sure I understood you correctly, but if you wired the transformer up backwards you'd get near 4000V out of it. That's plenty enough to kill the UT61E, it's not sufficiently protected against high voltage.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: crystal on January 11, 2015, 12:41:05 am
hi guys!
it's been 2+ months since i bought the 61E and everything was ok until today....
I had an old transformer that i wanted to measure and wanted to figure out  which pins are for the primary 220v and which are  for the secondary 12v. Unfortunately by my mistake  i plugged the transformer giving the 220v on to the secondary and the result was to blow the multimeter.Didn't understand why that happen despite that the scale was on the ac volts as it should.....Now it's dead.Won't turn on.The fuses are ok,the ptc's seems ok ,the rectifier diode also ok.Any ideas?

Check all the passive components. If it's still dead then the main chip is fried. You could try contact the crystek for the replacement chip, maybe they will sent you the new one. Then if you are skillful enough change it but you will probably need to recalibrate the instrument.

PS:
Why in the hell would you check the unknown transformer like that? You could be dead, what about if it was less that 12V secondary? I always check the unknown transformer by measuring resistance and try it on mains with nothing attached to it and me on a distance.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mikeva on January 11, 2015, 10:08:06 am
Yeap that,was stupidity from me.  |O Now I've learned my lesson....
Well, i'll check the components to see if something manage to stop all the voltage, but if it's the main chip that burned then i will throw it away and buy a new one.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Yago on January 11, 2015, 11:42:13 am
Don't throw it away, might be handy for parts and spares.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mikeva on January 11, 2015, 02:01:28 pm
No i won't.I'll keep it for spare parts   since it's brand new  :-\
the only thing it does right now  is when i connect the battery it's beeping like that: 1 beep then pause a sec,then beepping 7-8 times.Could this indicate something?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Wytnucls on January 11, 2015, 03:55:54 pm
It's trying to play the funeral march of Chopin:

Frédéric Chopin's Piano Sonata No 2 in B flat minor, Funeral March [HD] (https://www.youtube.com/watch?v=hZY5DBmgC_A#)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mikeva on January 11, 2015, 04:12:02 pm
 :D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rick Law on January 11, 2015, 10:09:49 pm
:D

That smilie means what?  You managed to revive your UT61E?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mikeva on January 12, 2015, 09:38:08 am
:D

That smilie means what?  You managed to revive your UT61E?

No,unfortunately!
I m laughing about the funeral march  that Wytnucls posted  above!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Steps on January 15, 2015, 07:58:56 am

You should drive the backlight leds with transistors. It will safer than old hack.

(http://img692.imageshack.us/img692/7282/dmm.png)
Taken from UT60E dmm schematic (http://320volt.com/wp-content/uploads/2011/05/Unit-UT60E-UT60E-schema-UT60E-circuit-fs9721lp3.gif).

In this configuration, couldn't the same protection be achieved by only using a single NPN rather than the complementary config shown here?


Hello Colleagues!
I going to do power off mod and backlit mod (with permanent light, not original). And I want that light will be off after DMM going to sleep. Can I connect +V of the LEDs to the positive side of C33, like for the IR transistor?
And should I add driving the backlight leds with transistors like in UT60E schematic?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: rr100 on January 26, 2015, 11:57:03 am
I had an old transformer that i wanted to measure and wanted to figure out  which pins are for the primary 220v and which are  for the secondary 12v. Unfortunately by my mistake  i plugged the transformer giving the 220v on to the secondary and the result was to blow the multimeter.Didn't understand why that happen despite that the scale was on the ac volts as it should.....Now it's dead.Won't turn on.The fuses are ok,the ptc's seems ok ,the rectifier diode also ok.Any ideas?

The idea (for the next time) is to check the resistance with the multimeter first, for sure the primary would be the highest.
I am surprised nothing else blew first - and I wouldn't trust the isolation on that transformer anymore not to start a fire or electrocute somebody.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: snowsnee on January 27, 2015, 03:02:05 am
Hey Guy Gals,

 New here, I got 2 UT61Es new I will post the backs open pictures and calibration. So far this to note UT61 series is the backlight UT61E does not have one. That series 61d or c b a may have one . Another note calibration right on 10.000, on two AD584KH with calibration stickers 10,001 cant calibrate right on the money can't calibrate nothing perfect. I asked some of the big time dealers AD584LH (not needed sticker notes I think ?) no calibration or AD584KH with calibration. One dealer selling AD584LH he said right now its AD584KH with calibration sicker to go by. Took a week of study nothing, so I just asked them the dealers which is best.

 So the one UT61E got from China $47 I got is accurate. UT61E $48.00 next I get I am getting from a dealer China 1000 miles away from each other. I will check the calibration to the other. I have 3 AD584KHs with sticker calibration set written (one coming still) to check accuracy then I will take apart show pictures of both if the same or not. (Note can't buy another multimeter better so I got 2 just because of the documentation this model.)

Edit: Now China dealer says ( yes, sure, there is a sticker) . AD584KH Dealer.   
Edit again: AD584LH ( it don't need calibration said big dealer eBay ) So it was like thought. And AD584KH does need the sticker calibration.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: snowsnee on February 01, 2015, 03:48:01 am
(http://i.imgur.com/6cap32l.jpg)

This is new Jan 31 2015.  Voltage reference: (10 VDC)  Was 10.000 VDC OK  on upper one not adjusted. Was 9.998 VDC Now 10.000 on the other corrected bottom one. You can adjust further. Looks like same boards new out of China.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: snowsnee on February 01, 2015, 04:13:09 am
(http://i.imgur.com/daTDJWC.jpg)

Looks different on the lower half not seen this on other sites new I think. Edit :  Note ..........Posted on Jan. 2015 this site page 52 of this post, never saw it.

Edit: On the calibration VR1 VDC VR ( teeter totters ) might be Ok for others sometimes rocks inside like, looking to change to post saying stays right till you use for awhile. 2 resistors 1K and 500 ohm variable resistor testing it before an after installation replacement. 4 LEDS for both also ordering for exterior switch installation for back-light.

 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ewetho on February 04, 2015, 04:20:43 am
My new UT61E meter has that latest board layout with the 3 PTCs too.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ewetho on February 08, 2015, 06:14:27 am
If one were to wish to fill SG1, SG2, SG3, and SG4 with MOVs any suggestions as to what to get brand and rating?

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: snowsnee on February 11, 2015, 12:13:28 am
(http://i.imgur.com/qxUIrk1.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: snowsnee on February 11, 2015, 12:19:29 am
(http://i.imgur.com/iWTQQge.jpg)

Yes its better now- glad I waited here my 2 after adjustment. VR1 DC is really touchy going change to a 25 turn variable or resistors and the 50 or 500 ohms variable studying.
Edit best of a post here. Studying Schematic: UT61E.

Copied from post here: I see that you did Chinese external Vref mod and replace the VR1 2k trimpot with two resistors and an 50Ohm trimpot, as this mod improve the calibration and stability?
 Thanks ! David
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: snowsnee on February 13, 2015, 07:21:36 pm
(http://i.imgur.com/YQRv2IV.jpg)

Carefully battery 9Volts negative hookup (V+ circle look) could negative . I did it by accident at the wrong angle to see Neg. sign no blow up did burns some parts on another UT61E this post mine took it fine.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on June 01, 2015, 04:36:44 am
Just a heads up for everyone who uses the logging capability (btw, i use ultradmm.com):

I did long time logging of UT61E thru the original USB cable UT-D04 (purchased from official UNI-T distributor) because i had lost the original serial cable. My logged data ended corrupt because in the Excel file there were missing lines (data rows). If the Excel file has 216,000 rows, then this would equal a time period of 108,000 seconds or 1800min or 30hrs. Check the time stamp of the first row and compare it with the time stamp of the 216000th row. The difference in time should be exactly 30hrs.

This was not true with my brand new UT-D04 data cable, which meant that the file was incomplete, which i was able to verify.

So i bought the original spare part, it is called UT-D02 and can be referenced from here:
http://www.uni-trend.com/en/product/list_370_1.html (http://www.uni-trend.com/en/product/list_370_1.html)

With this serial cable, i am getting the complete log, all 216000 rows for a time period of exactly 30hrs.

This may also be the explanation why UNI-TREND continues to package/ship the retail UT61E box with the serial cable and not the USB cable.

 O0
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on June 01, 2015, 09:01:02 am
Have you seen this backlight mod?     :)

https://www.youtube.com/watch?v=0XJloF0Pcc8 (https://www.youtube.com/watch?v=0XJloF0Pcc8)

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Nisei on July 27, 2015, 12:00:45 am
Hi guys, new here.
I have some basic knowledge about electronics but I do have enough experience with soldering and building things (although I often have no clue what I'm actually doing.)
I'd like to put a backlight in my UT61E without using the chip of the meter itself and I want to keep it dead simple. There are loads of dirt cheap touch sensor switches on eBay and my plan is to put one at the top inside of the meter and switch two 3528 LEDs with it (Like in the post above this one but that seems unnecessarily complicated). The switch needs 2.2 to 5.5V so my question is where on the circuit board can I get that voltage from without interfering with the measurements? If not possible there's always the way to take it straight from the battery but that's not very practical since the LED's could be switched on even if the meter is turned off.
Also, what's the very thin wire called that's often used for things like these? It looks to be very thin single strand bare copper wire but it's insulated with enamel. I'm trying to source it but it's hard when you don't know what it's called.

Thanks in advance.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Macbeth on July 27, 2015, 01:55:12 am
Hi guys, new here.
I have some basic knowledge about electronics but I do have enough experience with soldering and building things (although I often have no clue what I'm actually doing.)
I'd like to put a backlight in my UT61E without using the chip of the meter itself and I want to keep it dead simple. There are loads of dirt cheap touch sensor switches on eBay and my plan is to put one at the top inside of the meter and switch two 3528 LEDs with it (Like in the post above this one but that seems unnecessarily complicated). The switch needs 2.2 to 5.5V so my question is where on the circuit board can I get that voltage from without interfering with the measurements? If not possible there's always the way to take it straight from the battery but that's not very practical since the LED's could be switched on even if the meter is turned off.
You want to trace the VBAT going into the selector switch and find where it comes out. Chances are it will go to a 5V or 3V regulator and that is where you can source the proper current for your LEDs.
Quote
Also, what's the very thin wire called that's often used for things like these? It looks to be very thin single strand bare copper wire but it's insulated with enamel. I'm trying to source it but it's hard when you don't know what it's called.
Well, I've always known it as "enameled copper wire" but I think it is more popularly known as "magnet wire". Just make sure you use an adequate gauge if you are using it for high currents (like bright LEDs)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Nisei on July 27, 2015, 12:24:44 pm
You want to trace the VBAT going into the selector switch and find where it comes out. Chances are it will go to a 5V or 3V regulator and that is where you can source the proper current for your LEDs.
Hm, that would work if I knew what a regulator looked like... :)
So you can't tell from the schematic where on the board I can find a 3V or 5V connection that can be used for this?

Quote
Well, I've always known it as "enameled copper wire" but I think it is more popularly known as "magnet wire". Just make sure you use an adequate gauge if you are using it for high currents (like bright LEDs)
Hey thanks! Appreciate your help. Any idea what would be a reasonable gauge? I have no experience with such thin wires.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: lefedor on August 01, 2015, 10:31:33 am
Hello guys, can You please help me with the question about this multimeter.
Have briefly red this topic but strangely haven't fount the answer.
There are major negativity about unit's weak input protection.
I have old revision and want upgrade it's input protection. There are SG1/SG2 empty places on PCB and also reviewers often mentions that PTC could have better nominal (there also 2 of them). Those are really cheap and accessible parts.
So, question is: can anybody please recommend nominals for this unit?

I ask about 2 PTC's and 2 MOV's (and may be there should be 1-2 extra?) I could solder to this PCB:
(http://img197.imageshack.us/img197/1309/dscf0149o.jpg)

BTW, Also I think upgrade fuses from 250V to 600V version, but this is different story and after this mod unit price will raise close to the fluke version, but what would You do, I own 61E already.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on August 01, 2015, 05:22:35 pm
I would only put in some MOVs or spark gaps in the empty places. This could affect the accuracy of the capacitance function a little. The most common failure mode for the UT61E seems to be high voltage getting through and killing the main chip so the over voltage protection would be a good idea. I would look for 1kV or 1.5kV MOVs, or you can put lower ones in series too although that is not ideal. Don't bother changing the PTCs IMHO. Changing the fuses does not necessarily make the meter any safer. If the rest of the design cannot handle a sudden voltage spike if a fuse blows under with very high energy behind it the insides can still flash over and explode anyway. Actually the GS version of this model is de-rated compared to your version and it has all the proper input protections installed. I would not bother with the fuses neither but keep your wits about you when using the meter.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: wasyoungonce on August 10, 2015, 09:03:45 am
New UT61E, images here.  PCB layout different to some, no VREF LT1970 pads on PCB...sigh!

Also, 1st stupid question...the "Data Output in progress" Icon is "on" the LCD all the time.  Manual seemed to indicate I could turn this off by holding the REL button for over 2 seconds.  Doesn't change icon!  Is this RS232 data out?

I'm starting to look at the vids and other images appear to indicate this is on all the time?  Is this right?  Sorry if it's been done to death!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on August 10, 2015, 10:34:29 am
The icon is always on, because the meter is always sending data.

Read the IC datasheet (should be here in the thread somewhere, if not google it), the chip has this data logging feature that can be turned on or off through some pins but on ut61e it's configured by uni-t as always on.  When datalogging is enabled, the auto power off is disabled and so on.   
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: wasyoungonce on August 10, 2015, 09:37:24 pm
The icon is always on, because the meter is always sending data. .....

Thanks.....kinda guessed it was this but thought it best to ask.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Nisei on August 16, 2015, 03:43:29 pm
Done!
Cost me less than a dollar :)

https://youtu.be/EHStaKB0BwI (https://youtu.be/EHStaKB0BwI)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: george graves on August 18, 2015, 06:42:36 am
I like it!!! Pics of internal wiring?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: wasyoungonce on August 18, 2015, 07:45:21 am
Niesi...saw you post on capacitive touch...nice...can you post cct and parts?   The Audio forum requires login ...I have so many I'm reluctant for more for one look.

Many thanks and well done!

Brendan
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: george graves on August 18, 2015, 09:15:07 am
It looks like he did something a bit different then that DIY audio post.  Yes, details would be great - would love to write about it for hackaday.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Nisei on August 18, 2015, 02:43:15 pm
I've started a separate thread about it: click (https://www.eevblog.com/forum/testgear/uni-t-ut61e-backlight-mod-with-touch-sensor-%28tutorial%29/msg734204/#msg734204)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: naughtilus on August 23, 2015, 07:41:38 am
Quote
If we neglect the fact of the price difference and
the fact that I am working on voltages below 230V and
did never use temperature measurement with my UT70A,
would you (or others) still go for the UT139C?

If yes, why?

-Didix

Hi, since i own the both multimeters, here's my 2 cents:
The UT61E feels much more responsive, the autoranging speed is faster than the UT139C, especially for measuring resistance. The continuity tester is also slightly faster on the UT61E. If you ever need data logging capabilities (i do) the UT61E comes in really handy. I have used this multimeter with voltages up to 220 V AC while doing some basic electrical maintenance without a problem. On the other hand, the UT139C has better input protection, backlight, temperature measuremenr (only 1 degree resolution), NCV, low pass filter, and current clamp capability (up to 60A) which comes in handy while doing electrical work. I use this meter mainly while i am on field work working on automation equipment and cabinets. Having said all that, the UT61E is better suited in lab environments working with "low voltage" electronics e.g. MCU's, PLC's or other types of digital control (or similar) ELECTRONICS, while the UT139C is better suited for ELECTRICAL work. If the missing data logger and the slightly slower autoranging of the UT139C are not a deal breaker for you, go for that one. Both meters are great value for money so you won't make a mistake with either of them.

Hi Goce,

The continuity tester on the 139C is lightning fast and latched. Only issue is if you have pitted and/or dirty leads, which they usually are even when new out of the box. Cleaning them with contact spray helps a lot.

The 139C is definitely for electrical work and not so much for electronics. UT61E is the champion in that domain.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: naughtilus on August 23, 2015, 08:50:09 am
Actually if I understand things correctly, the GS version is sold in Germany and it has a different design. The GS version has better input protection but has a lower CAT rating. The information is here on the forum somewhere and in this thread I think.

After having both the UT61E and the UT139C I recommend the UT139C instead, if you don't need the PC connection.

LA, did you try the 5000V insulation tester on your 139C? 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: 5ky on August 23, 2015, 09:02:38 am
Done!
Cost me less than a dollar :)

https://youtu.be/EHStaKB0BwI (https://youtu.be/EHStaKB0BwI)

Excellent mod!  If you don't mind me asking, what probes are those?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: iloveelectronics on August 23, 2015, 12:57:09 pm
Excellent mod!  If you don't mind me asking, what probes are those?

Those look like Fluke TL175.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Nisei on August 23, 2015, 02:20:44 pm
Correct, TL175
I got them with my Fluke 177. Sold the 177 but kept the TL175 leads. I really like them.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mos6502 on August 23, 2015, 09:54:33 pm
Only issue is if you have pitted and/or dirty leads, which they usually are even when new out of the box. Cleaning them with contact spray helps a lot.

Had the same problem. Tried all kinds of chemicals. Acetone. Alcohol. Window cleaner. It helped a little, but it wasn't 100%. Then I tried this:

(http://www.pelicanparts.com/catalog/images/weiss_images/TTN-41226.jpg)

(A small brass wire brush.)

Scrub scrub scrub. Result: PERFECT. When I rub the probes together in buzzer mode, the resistance never even goes above 0.2 Ohms. Before, when did the same thing, the resistance would spike to hundreds of ohms. The formerly shitty Uni-T probes are a joy to use now.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: naughtilus on August 24, 2015, 12:06:22 pm
Great idea with the brush.  :-+ The stock leads are not great, but certainly not terrible like the ones found on 830 DMMs.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ocw on September 07, 2015, 02:59:05 pm
I haven't seen much information on the sensitivity of the frequency counter in the UT61E other than it's not the best.  The manufacturer rating of 220 MHz along with the meter's banana plug input is a bit of a oxymoron.  220 MHz and the normal banana plug leads don't get along.  So, I made a banana plug to BNC shielded cable.  I fed the output of a Ramsey COM3010 service monitor directly to the meter when its 0 dBm output level was adequate.  When needed, I added a 16 dB amplifier.  It's 40 mW output was inadequate above 101 MHz.  Even starting below that frequency, greater frequency resolution is generally required dictating use of a frequency counter anyway.

I measured the sensitivity of the frequency counter portion of the UT61E as:

        UT61E      
FREQ    COUNTER SENSITIVITY      
         
1 Hz            >3.43 V   > +24 dBm   
2 Hz           171 mV   -2.3 dBm   
10 Hz   105 mV   -6.6 dBm   
60 Hz   105 mV   -6.6 dBm   
1 kHz   105 mV   -6.6 dBm   
10 kHz   117 mV   -6.0 dBm   
100 kHz   117 mV   -6.0 dBm   
0.5 MHz   165 mV   -2.6 dBm   
1 MHz   165 mV   -2.6 dBm   
4 MHz   200 mV   -1.0 dBm   
12 MHz   243 mV   +0.7 dBm   
25 MHz   243 mV   +0.7 dBm   
30 MHz   243 mV   +0.7 dBm   
35 MHz   243 mV   +0.7 dBm   
40 MHz   267 mV   +1.5 dBm   
50 MHz   385 mV   +4.7 dBm   
60 MHz   385 mV   +4.7 dBm   
65 MHz   554 mV   +7.9 dBm   
70 MHz   777 mV   +10.8 dBm   
75 MHz   873 mV   +11.9 dBm   
80 MHz   873 mV   +11.9 dBm   
85 MHz   1.10 V   +13.8 dBm   
100 MHz   1.20 V   +14.6 dBm   
101 MHz   1.35 V   +15.6 dBm   

Given the low resolution of the counter I didn't go into detail confirming its accuracy, but I never saw a sign of any significant error.

I also measured the frequency response of the AC voltmeter portion of the meter.  Since I'm more concerned about its validity for frequency response measurements, I measured the response +/- 1 dB.  I found that to be 5 Hz to 68 kHz.  The response was down 1 dB at 5 Hz and up 1 dB at 68 kHz.  At 60 Hz I measured its AC voltage accuracy as +0.155% (well within its 0.8%+10 rating).

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mos6502 on September 07, 2015, 03:57:55 pm
ocw, that's very interesting. I think above a few MHz, the capacitance of the leads becomes a big issue. Have you tried using extremely short leads? Or a BNC to banana Adapter?

Here's a schematic of the UT61E: http://docdro.id/EbNqMPt (http://docdro.id/EbNqMPt)

As you can see, the input circuitry of the frequency counter is very simple (the stuff around R35).

I'm having some issues with the frequency input of my UT139C, but it did measure up to 27MHz correctly, even though it's only spec'd to 10MHz.

Have you tried the duty cycle measurement? It would be interesting to know up to what frequency that would be halfway accurate.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ocw on September 07, 2015, 05:39:54 pm
I must have made a good banana plug to BNC cable--I didn't see a significant change when instead of using the cable, making it clumsy and using a banana to BNC adapter instead.
I'm not sure what duty accuracy you are looking for, but this is what I measured on the UT61E:

Freq    Waveform           D Cycle
100 MHz   Sine           5.0%
90 MHz   Sine           6.7%
80 MHz   Sine           15.3%
70 MHz   Sine           25.0%
60 MHz   Sine           30.7%
50 MHz   Sine           34.9%
40 MHz   Sine           41.3%
30 MHz   Sine           42.1%
20 MHz   Sqr 50%   44.8%
15 MHz   Sqr 50%   45.9%
15 MHz   Sqr 32%   35.0%
15 MHz   Sqr 68%   58.6%
10 MHz   Sqr 50%   46.9%
5 MHz   Sqr 50%   48.0%
1 MHz   Sqr 50%   49.4%

The duty cycle reading being displayed on the UT61E depended on the input voltage.  If that voltage was just enough for an accurate frequency reading, the duty cycle reading would be low.  Double the voltage and the duty cycle reading would be much more accurate.  Since I was unable to increase the RF voltage for the higher frequency readings, the accuracy of their duty cycle readings seen was compromised by that.

 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mos6502 on September 07, 2015, 06:10:29 pm
Great job, thanks! Of course, the measurment of the duty cycle depends on the trigger level, so it's really only meaningful for square wave signals. But it looks like the duty cycle measurement is useful to at least 1MHz.  :-+

Duty cycle measurement is really useful for a lot of things. E.g. if you wrote a multitasking scheduler for your microcontroller, you can set a pin at the beginning of your task and reset it at the end of your task, and by measuring the duty cycle you can directly see how much of the CPU time that task consumes in percent.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ocw on September 08, 2015, 02:33:55 am
I forgot about the higher output power available from my HP 3200B VHF generator.  Taking it to a metered output of +23.5 dBm/224 mW/3.346 V (1.7 dB beyond its rating) the UT61E was able to measure its output frequency up to 225 MHz.  Uni-Trend hasn't over-rated it.  But, there's a reason why their specs don't show its counter's sensitivity.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: xZero on September 11, 2015, 04:34:15 pm
Is this one still worth consideration in 2015? Or is there something better for same price?  :P
Thanks in advance!

I was on cheap one, and finally gonna move to something better with PC connection.
I work primarily with electronics and informatics (hardware).

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mos6502 on September 11, 2015, 05:02:12 pm
Is this one still worth consideration in 2015? Or is there something better for same price?  :P
Thanks in advance!

I was on cheap one, and finally gonna move to something better with PC connection.
I work primarily with electronics and informatics (hardware).

Do you need the PC connection? If not, I'd go with the newer UT139C. Much better construction, faster display, actually has input protection, temperature measurement, real fuses and has a backlight. Only 6,000 counts, but unless you have specific requirements, that's perfectly adequate.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: xZero on September 11, 2015, 05:37:39 pm
Thanks for the reply.

But yes, I do need PC connection, and that's the feature I've been missing on all multimeters I had (cheap ones).
Looking from my point of view, by my needs, UT61E seems like perfect choice, I've just wondering can I get something better/newer with same capabilities for the same price?
Since UT61E is few years old, I expected price to be lower as well, however it seems that it holds it price since then.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mos6502 on September 11, 2015, 06:50:31 pm
22,000 counts and PC interface is pretty much unparalleled at this price point. So yeah, buy it. Forgot to mention, the burden voltages are also worse on the UT61E vs. the UT139C. Really, I would get the UT139C as well. Each has features that the other one is missing. I'm thinking of getting a UT61E myself to complement my UT139C.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: xZero on September 11, 2015, 07:45:57 pm
Since I'm limited with price at the moment I'm gonna buy UT61-E as it have what I need and later I may go for UNI-T UT71D. Having spare multimeter can't be bad.

Or, what if I buy Mastech MY64 as first hand, since I'm out of any right now... It's pretty cheap, and seems to be decent temporarily.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mos6502 on September 11, 2015, 07:59:50 pm
Wat. That one doesn't have a PC connection. ???

Anyway, this one is cheaper and better than the Mastech you mentioned:

https://www.youtube.com/watch?v=URKSs02qz5c (https://www.youtube.com/watch?v=URKSs02qz5c)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Lightages on September 11, 2015, 08:02:23 pm
Just remember that the UT61E,and the UT71D do not meet their CAT ratings. Use them for electronics use and they are are good buys. The UT139C is a much better built and safer meter but has less features.

I have zero confidence in anything made by Mastech and would recommend the Uni-T models before anything made by Mastech.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mos6502 on September 11, 2015, 08:14:12 pm
I have zero confidence in anything made by Mastech and would recommend the Uni-T models before anything made by Mastech.

Bingo!  :-+

Another option would be the DT-4000ZC:

https://www.youtube.com/watch?v=kXzAD74C5As (https://www.youtube.com/watch?v=kXzAD74C5As)

http://www.ebay.de/itm/Digitek-DT-4000ZC-TekPower-TP4000ZC-Data-Logging-Multimeter-with-Temperature-/200912705694 (http://www.ebay.de/itm/Digitek-DT-4000ZC-TekPower-TP4000ZC-Data-Logging-Multimeter-with-Temperature-/200912705694)

Pretty decent meter, very cheap and it has RS232.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: xZero on September 12, 2015, 01:29:01 am
Wat. That one doesn't have a PC connection. ???
...


Yeah I noticed that, but for price I didn't expected it.

Thank you for your effort guys, I'm realy happy to see al that responses and I had took a look at every of DMM recommended, and so I decided to go for UT61E for now, and after when I get some more money for some better one. It's good to have more than one.


As I said I'm electronic hobbyist, and sometimes I "mess" up with household installations and such voltages, but my very first generic DMM (DT-SOMETHING) had cost me only 10USD and It lasted for 5 years, and I did use it to measure amperage up to 20A, measure DC/AC voltage up to 200/500V for electronic tasks, for car electronics etc and it did all pretty well. It had bad probes, and unusable capacitance tester. I killed it by measuring voltage from DC/AC converter (12VDC -> 90VAC) because I forgot to change from DC to AC. That one was almost visually/feature identical as Mastech MY64 with exception that protection cover was yellow.



Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: niclasf on September 22, 2015, 11:12:51 am
I have done a combination of many of the UT61E modifications.
I have used a PIC16F688 to add more modes to the yellow and blue function buttons.
https://www.youtube.com/watch?v=KLrDdRcWR2Y (https://www.youtube.com/watch?v=KLrDdRcWR2Y)

I have also added a LPF mode, but I am not sure how I can verify that it works. ::)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: NicolasCalisto01 on October 10, 2015, 02:59:31 pm
Yes, is a nice multimeter hack
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: groff on October 28, 2015, 06:09:39 pm
niclasf wrote:

Quote
I have done a combination of many of the UT61E modifications.
I have used a PIC16F688 to add more modes to the yellow and blue function buttons.

Yes, very good work. :-+  I found your c file on foogadgets but can I get hex file? Can you attach it on foogadgets or on this forum?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: niclasf on October 29, 2015, 06:35:45 am
Now you can download it in the download section in bitbucket, https://bitbucket.org/foogadgets/ut61e-modification/downloads/ut61e-mod.hex (https://bitbucket.org/foogadgets/ut61e-modification/downloads/ut61e-mod.hex)

Enjoy!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: groff on October 29, 2015, 05:51:13 pm
Thanx  :clap:
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: jbuszkie on October 30, 2015, 09:35:59 pm
I have done a combination of many of the UT61E modifications.
I have used a PIC16F688 to add more modes to the yellow and blue function buttons.
https://www.youtube.com/watch?v=KLrDdRcWR2Y (https://www.youtube.com/watch?v=KLrDdRcWR2Y)

I have also added a LPF mode, but I am not sure how I can verify that it works. ::)

Do you have pictures of the mods?  I tired to go to the forum post in the foogadgets blog but it doesn't seem to work.

Thanks!

Jim
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: niclasf on November 09, 2015, 11:26:51 am
I have uploaded the pictures from the modification, https://bitbucket.org/foogadgets/ut61e-modification/downloads (https://bitbucket.org/foogadgets/ut61e-modification/downloads)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MrMacman2u on November 15, 2015, 05:07:01 am
I have done a combination of many of the UT61E modifications.
I have used a PIC16F688 to add more modes to the yellow and blue function buttons. (popped out the link -MM2U)

I have also added a LPF mode, but I am not sure how I can verify that it works. ::)



Excellent... no... Outstanding work niclasf! :-+

I just bought this meter and this is, literally, an even better modification than the one I was in the middle of making using an ATTiny 85 since I wasn't going to bother breaking out the LPF!

Now I need to step it up and figure out how to hack in the temperature function using the ADF pin since that the chip supports temp too.

I'm working on other hardware upgrades as well including setting in metal inserts to use machine screws for the battery compartment and case, solid input jack upgrades to replace the cheapo splits, and installing the missing MOV's.

I'll document all the changes and post them here.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Hydrawerk on April 09, 2016, 12:29:15 am
Is it normal that I get 312pF when nothing is connected?? I found these UT-61E at a school lab
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Hydrawerk on April 09, 2016, 12:35:01 am
I got much better results on some old multimeters. UT70A from 2009, DT-890G from early 2000s and the M-3650D is more old, probably from mid 1990s.
(I do not know if this was discussed earlier in this thread...)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on April 09, 2016, 01:34:23 am
The capacitance is a bit on the high side.

Mine shows 84 pF with the leads connected, about 58 pF without any leads.  The manual specifies 50pF as normal/acceptable, and that you should use the REL button to zero it out.

Still, i wouldn't worry very much about it, though i would test the capacitance function with several known capacitors.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: RobertoLG on April 09, 2016, 01:46:45 am
Is it normal that I get 312pF when nothing is connected?? I found these UT-61E at a school lab

just press the Rel mode
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Hydrawerk on April 10, 2016, 12:49:18 am
Thank you for the advice. My thoughts on the meter:
The two buttons (blue and yellow) are confusing.
Why no LCD backlight? Strange on a 22000 counts DMM.
The autoranging is quite fast.
Beeper is fast.
I like the OFF position of the rotary switch. Now the DMM cannot turn on when carried in a backpack.
Well, i prefer Brymen (not owning one yet) but this UT61E is probably an OK multimeter for most needs, especially if you do not work with high energy circuits.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MrSlack on April 10, 2016, 12:02:10 pm
I've had one a few months and I have no problems with it. Gets a bit dicky if the battery goes flat. Mainly use it in manual ranging mode if I'm honest

I get ~220pF with a couple of Pomona minigrabber to 4mm leads attached to it. As someone said, use REL for capacitance measurements to deduce input circuitry and lead capacitance. The supplied component tester module is crap - I threw it away.

As for high energy I regularly use it up to ~110v DC (inside a Tek scope) and AC mains, voltage only! I make a habit of not actually probing anything high energy live and use clip probes then apply power so the meter is not making a circuit with me at all at any point and I wear eye protection when working on anything likely to go pop.

Regarding multimeter lore, I suspect more people injure themselves not from the meter blowing up but doing something stupid to start with (probe shorts, accidentally becoming part of a ground loop etc etc)

Interesting bit: I paid £40 for mine - total bargain!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on April 10, 2016, 02:14:07 pm
Can high energy but low voltage as stored in a large capacitor or in a car battery damage the meter as badly as the mains or HV?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MrSlack on April 10, 2016, 02:22:48 pm
Probably not a capacitor or a car battery as the general nature of the high impedance inputs means that the capacitor can't discharge quickly enough. If you stick it on amps and short it then it'll just pop a fuse. Inductors on the other hand, when the magnetic field collapses can produce hundreds to thousands of volts which can jump around or through any protection and high impedance inputs.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Thilo78 on April 10, 2016, 02:25:08 pm
I got much better results on some old multimeters.
Not sure if it helps, but I'll throw in the result from my UT71E.
No leads: 0 pF
Leads attached: 11 pF
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on April 10, 2016, 02:29:38 pm
My 61E shows 66pF sans leads, 85pF with Brymen leads
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Salas on April 10, 2016, 02:33:22 pm
Probably not a capacitor or a car battery as the general nature of the high impedance inputs means that the capacitor can't discharge quickly enough. If you stick it on amps and short it then it'll just pop a fuse. Inductors on the other hand, when the magnetic field collapses can produce hundreds to thousands of volts which can jump around or through any protection and high impedance inputs.

A static discharge could also find its way to the main chip by jumping around If not absorbed by protection I suppose?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MrSlack on April 10, 2016, 03:28:53 pm
It could.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mike60 on April 11, 2016, 07:53:46 pm
Hello U61E users  :)
I received today my 61E. 49$ Ali....
I want to make some modification.
Back light. I order TP223 it is on the way. I order MCP1703 - received. I have some leds.
If everything are ok i go to next mod.
I suppose this product are old. Why ?
Please look attachment.
Regards
Mike
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on April 11, 2016, 08:19:44 pm
No idea, but I would suggest as well you order some 5mm 600VAc MOV devices and put them on the board in the 2 places  SG1 and SG2 marked on the board.

RS  760-6964 or 711-8149 or 289-7109 or 178-059  would all do there, low capacitance and with a clamp voltage well above what you would normally apply to the meter in most cases, but hopefully more than enough to protect the meter from major overvoltage. First would provide most protection, but will limit maximum voltage to mains voltage only, the others will enable use at 400VAC with some care.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mike60 on April 11, 2016, 08:32:27 pm
Thank you.
I will try.
Regards
Mike
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mike60 on April 11, 2016, 08:39:08 pm
SeanB
RS  760-6964 or 711-8149 or 289-7109 or 178-059 

I find all but what to buy ? And are different sizes. Please what to order ?

Regards
Mike
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on April 11, 2016, 08:50:34 pm
First one is small (9mm) and will allow you to work with mains AC up to 300VAC or 400VDC, so will be fine with the meter.  So probably the best compromise as you really do not want to use these meters at higher voltage.  Lowest capacitance as well and likely the fastest acting.

You also get them in a pack of 10, so will have 8 left over just in case. Pretty cheap as well.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Mike60 on April 12, 2016, 04:51:52 am
Morning
I will order today.
Have a nice day
Mike
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on April 18, 2016, 01:53:32 pm
Hi,

I am thinking of adding some input protection to the UT61E. 

MOVs are fast but low current and will add capacitance.
GDTs are slower but high current and very low capacitance.

Can we use a combination of MOVs & GDPs for ever better response?

On the other hand I see that the tracks from the GDPs are very thin.
So is there any point to add the protection with such thin tracks?
Look for example the one that goes from SG1 to R28.

forget the above...

Thanks.
George.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fungus on April 18, 2016, 02:22:27 pm
Can we use a combination of MOVs & GDPs for ever better response?

Yes. Add enough MOVs to protect you until your GDTs react. The more the better (well, two MOVs is probably enough...)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on April 18, 2016, 03:33:33 pm
In series?  In Parallel?
Can you suggest a combination that will suit the UT61E?
Thanks.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on April 18, 2016, 06:29:53 pm
Slap the 3 low capacitance MOV units in, and be done with it. The limiting factor will be the PTC in any case, 1kV and it will fry itself apart in a second or so. Choose the voltage to suit your normal use, and as they mostly come from RS in packs of 10 you will have some spares. If you do blow them up the meter will not survive in any case.

In my case I just used 2 275V MOV units ( 7mm) in series, as I did have the remains of a 10 pack around, so using the 6 was easier than either placing an order and wait till I had the minimum order price in other parts, or paying the $20 courier charge RS puts on here for small orders. Still have 1 left, after replacing 3 MOV units on other equipment.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on April 18, 2016, 06:41:07 pm
Hello SeanB,

Do you know if the varistors will affect the Capacitance measurements?
Did you check it on yours?

What about these GDPs?
http://www.ebay.com/itm/2PCS-2RM470L-8-470V-2R470-10KA-Ceramic-gas-discharge-tube-Mine-management-/261991644243 (http://www.ebay.com/itm/2PCS-2RM470L-8-470V-2R470-10KA-Ceramic-gas-discharge-tube-Mine-management-/261991644243)


Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: SeanB on April 18, 2016, 07:16:51 pm
RS ones will add 300pF to the capacitance, but as you pretty much always use REL mode in capacitance from new it does not make a difference except on the lowest values.  Might slightly drop frequency response, but as it is only specced to 1MHz in any case the slight drop off will not worry much. If you want frequency you are pretty much only measuring mains or up to 20kHz VFD values in any case, higher you want a real frequency counter, and AC will not worry at all, the RMS converter is the limiting device.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on April 18, 2016, 08:05:36 pm
What about this comment from a different thread ?

https://www.eevblog.com/forum/testgear/ut61e-drift-and-recalibration/75/ (https://www.eevblog.com/forum/testgear/ut61e-drift-and-recalibration/75/)

"I think that MOV-s are inadequate for UT61E, because you lost the hight impedance input on mV range.
You can find GDT down to 70-100V."
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Kakalas on May 13, 2016, 11:06:32 am
Hello,

Maybe someone could help me to solve this problem...  :-//
I have a multimeter UT61E for some time, I use it a little, it's almost new. Recently I noticed that UT61E began to show a false VDC (when nothing is connected shows about -1.15 VDC). I tried to carry out calibration according to the guide (link below), but no result, since the margin of error is quite large and goes out of calibration range. Would anyone have any ideas how to fix it?

http://gushh.net/blog/ut61e-calibration/ (http://gushh.net/blog/ut61e-calibration/)

(https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/?action=dlattach;attach=224647)

(https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/?action=dlattach;attach=224649)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: retiredcaps on May 13, 2016, 09:25:34 pm
Recently I noticed that UT61E began to show a false VDC (when nothing is connected shows about -1.15 VDC).
Questions.

1) Have you tried a new battery?
2) If you short out the probes with the meter on DCV, does it show 0.0?
3) Post clear focused pictures of your meter so we can see the pcb (both sides) and look for any obvious damage.
4) Does ACV work?
5) Does resistance work if you measure a 1k ohm resistor?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MrSlack on May 13, 2016, 09:57:48 pm
Mine did all sorts of weird stuff when the battery went flat. First point of call on these I think.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 03:22:14 pm
I am interested in knowing more about how people who have recommended changing the meter have validated their changes.

Just a little thought on this....   I ran both the 61D/E and they failed with a basic ESD pulse.    I also ran a UT181A that failed with a single ESD event.  The UT181A has PTC, MOVs and secondary clamps.       

On the flip side, I have ran a few meters that have survived not only ESD but some much higher energy transients that had no MOVs.   The last one I ran was the UT10A which not only survived the basic ESD but went on to survive a 3KV 100us FWHH with a 2 ohm source with the meter set in all modes. 

In the case of the UT181A, the cost of the meter (and my own interest) drove me to have a look at the design in more detail.   In this case the layout has a few problems that needed to be addressed.  A little Dremel, X-acto and dope.    And no, adding a clamp to the output of the regulator was not one of them.   

With the recommendation to add MOVs, I am curious what the goal is?  Safety, robustness?  I would like to know how this was validated?   Do we even know if there was ANY improvement?  Worse, did adding them make the meter less safe?      I can see someone getting a false sense of added safety.   

It could very well be that UNI-T actually tested the meter with and without the additional parts and had the same performance and decided to save some money.  I have no idea.   
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on May 14, 2016, 03:30:20 pm
I have ordered two of these :

http://www.tme.eu/gb/details/siov-s20k625/tht-varistors/epcos/b72220s0621k101/ (http://www.tme.eu/gb/details/siov-s20k625/tht-varistors/epcos/b72220s0621k101/)

In what circumstances adding these MOVs will make the multimeter less safe?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 03:40:40 pm
Do you feel sprinkling in a few parts will make it more safe or robust?  If you do and in fact it has no effect then that in of itself would make it less safe.   How will you know if there is an improvement?

I have ordered two of these :

In what circumstances adding these MOVs will make the multimeter less safe?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on May 14, 2016, 03:50:00 pm
Quote
How will you know if there is an improvement?

I guess you would not know and you'd better not find out the hard way.
I will send it to you to throw some kVs and see what happens...   :)

But seriously, if there is a transient and the MOVs are working, wouldn't they clamp it down
safely?   Before them there are two PTCs as well. 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 04:26:10 pm
I don't know about the safety side at all.   I just don't throw that sort of energy at them.  People recommending to add parts should have some data based on fact.   I gave up on Santa Claus and the Tooth Fairy years ago.   

The 181A fully populated with all of it's fancy protection failed with just one hit of a very low ESD event.  Had they removed the parts and saved that money, it would have failed just the same..   On the flip side, had I received the meter without the protection circuitry populated and then correctly guessed what the parts were and added them, it would have still failed.  :-DD   The layout is important and can't be ignored. 

What you have suggested may not be a bad idea.  If we forget about safety, I could run your meter to see if there was an improvement in robustness but you may not like the end results.   What's that meter cost?  When I made changes to the UT181A, I could have just said I fixed it or just reapplied a single ESD transient and left it at that.   I thought it was better to throw everything I could at it and leave no question the meter's robustness had indeed been improved.
 
Quote
How will you know if there is an improvement?

I guess you would not know and you'd better not find out the hard way.
I will send it to you to throw some kVs and see what happens...   :)

But seriously, if there is a transient and the MOVs are working, wouldn't they clamp it down
safely?   Before them there are two PTCs as well. 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on May 14, 2016, 04:37:08 pm
Do you have the specs of the UT181a MOVs it came with?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 04:44:15 pm
Yes.  It was all covered in that second half of the video starting about 8 minutes into it.   

Do you have the specs of the UT181a MOVs it came with?

https://www.youtube.com/watch?v=1kYcY2ogmqo (https://www.youtube.com/watch?v=1kYcY2ogmqo)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on May 14, 2016, 05:11:33 pm
Layout design is key of course but from what manufacturer were the 07D751K MOVs?
There are many Chinese replicas around with the same part numbers.  Maybe they
were not so fast as their datasheet claims.  After the protection modification, you should
have used the same MOVs to see if it survive.  (If they were not damaged of course).
Did you use the same MOVs?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 05:14:26 pm
Comparing the UT61E's shown and the one 5ky had sent, they are a lot different.   Note the place for 4 MOVs.   I guess even within one revision of the meter you can't be sure what you are getting.   Roll the dice..
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 05:24:51 pm
Same

Layout design is key of course but from what manufacturer were the 07D751K MOVs?
There are many Chinese replicas around with the same part numbers.  Maybe they
were not so fast as their datasheet claims.  After the protection modification, you should
have used the same MOVs to see if it survive.  (If they were not damaged of course).
Did you use the same MOVs?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on May 14, 2016, 05:27:39 pm
Quote
I guess even within one revision of the meter you can't be sure what you are getting.   Roll the dice..
True...

My UT61E has a different layout.
(http://s5.postimg.org/8xthtn0fb/UT61_E_Protection_PCB_Section.jpg) (http://postimage.org/)

The isolation PCB gaps between the PTCs are also missing...


Same MOVs and survived after the mod.  Clearly poor design.
Both the 181A and the UT61E do not have proper HV isolation slots.
Maybe that's why they fail.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 05:42:19 pm
Yours looks  like the others I have seen posted.  :-//   Even if I wanted to do an A/B compare, getting meters that are the same appears to be a problem.     

At the start of that video, I had shown what the ESD transient looked like after a few people had asked.    It's pretty fast.    Funny that the UT10A with it's one PTC survived so well compared with so many of their much more costly meters.   Again, roll the dice..
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on May 14, 2016, 05:52:40 pm
Quote
Funny that the UT10A with it's one PTC survived so well compared with so many of their much more costly meters

Indeed. 
There must be an explanation though. 
How did it survive with just the PTC which is just for over current  protection?   :o
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 06:36:18 pm
Oh, I have an explanation.   When you roll the dice, there is a certain amount of luck involved!   :-DD   
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: smithnerd on May 14, 2016, 08:01:21 pm
Comparing the UT61E's shown and the one 5ky had sent, they are a lot different.   Note the place for 4 MOVs.   I guess even within one revision of the meter you can't be sure what you are getting.   Roll the dice..

Those 4 MOVs are populated in the German version (which is down rated to CATIII 300V, CATII 600V). I think any UT61E manufactured after 2015 shares the same PCB design as the 'safer' German one.

Image of the German version from earlier in this thread:

(https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/?action=dlattach;attach=128052;image)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on May 14, 2016, 08:33:39 pm
...and below is how I received my UT61E 'Special Edition'...

(http://s5.postimg.org/5kl96x6uf/UT61_E_Special_Edition.jpg) (http://postimg.org/image/nneby52oz/full/)

C8b is a capacitor on top of another and flux residue all over the place!    :wtf:
Am I the only one with a special edition ?    :)

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 09:31:49 pm
5KY's was rated for CAT III 1000V, CAT IV 600V without the MOVs.   It must be a safer version than the German one with the MOVs!   Besides your meter having the MOVs, at a quick glance:

PCB is marked different
Metal can
Cap next to metal can is mounted differently
Slits in board near can are different
Added pot near can
Blue pot is backwards
Q5/6 are larger package
Fuses are sized differently (smaller parts used on higher CAT rated meter)

Those 4 MOVs are populated in the German version (which is down rated to CATIII 300V, CATII 600V). I think any UT61E manufactured after 2015 shares the same PCB design as the 'safer' German one.

Image of the German version from earlier in this thread:
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 09:39:46 pm
 :-DD :-DD

Solder and assembly looks good on this board.   Maybe one of these versions could actually handle some sort of transients without any mods...   

...and below is how I received my UT61E 'Special Edition'...

C8b is a capacitor on top of another and flux residue all over the place!    :wtf:
Am I the only one with a special edition ?    :)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Hydrawerk on May 14, 2016, 10:02:15 pm
OK, so UNI-T is able to produce a good multimeter, but you cannot recognise it at the shop.  :-- Oh, wait, you can buy an Amprobe meter, that is UNI-T design but with proper fuses, MOVs and PTCs.  :P
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 14, 2016, 11:09:34 pm
Maybe we could modify AMPROBE's AM61E or Fluke's 61E+.   No wait,  those would actually be fairly robust.   Best to stick with the UT61E.

OK, so UNI-T is able to produce a good multimeter, but you cannot recognise it at the shop.  :-- Oh, wait, you can buy an Amprobe meter, that is UNI-T design but with proper fuses, MOVs and PTCs.  :P



Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Kakalas on May 16, 2016, 06:02:39 am
Recently I noticed that UT61E began to show a false VDC (when nothing is connected shows about -1.15 VDC).
Questions.

1) Have you tried a new battery?
2) If you short out the probes with the meter on DCV, does it show 0.0?
3) Post clear focused pictures of your meter so we can see the pcb (both sides) and look for any obvious damage.
4) Does ACV work?
5) Does resistance work if you measure a 1k ohm resistor?


Hi,
-> 1) Yes, I have tried a few new batteries, meter VDC readings are almost the same.
-> 2) No, it doens't, see pictures bellow.
-> 3) See pictures bellow, sorry for poor quality, for now I only can make photos with phone camera. I do not see any visible damage.
-> 4) Yes AC works correctly, see pictures bellow
-> 5) Yes resistance works correctly, see pictures bellow.

I also noticed:
Resistance -> buzzer function, no sound if contacts are shorted
Resistance -> diode function doesn't work correctly, see pictures bellow (shows ~1,6 V when nothing connected, if contacts shorted buzzer sound apears  ??? )
Capacity measurements works correctly.
Frequency (AC) measurements works correctly.
Current uA, mA, A measurements works correctly.
 :-\


(http://s32.postimg.org/rbrl8t0yd/Tester3.jpg)


higher quality:
http://postimg.org/gallery/3igu9z1le/ (http://postimg.org/gallery/3igu9z1le/)

(http://s32.postimg.org/ns56zmhat/tester4.jpg)


Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ModemHead on May 16, 2016, 03:00:46 pm
@Kakalas, you probably should start your own dedicated thread in the Repair section to avoid stepping on other discussions here.

Connect another DMM in parallel with the UT61E, with both in VDC mode.  If the working meter indicates a "real" voltage present at the UT61E's input, then current is leaking into the front end through some fault path back to the power supply.

Inspect closely for obvious stuff first: PCB contamination, wayward solder bits, carbonization from unfortunate over-voltage events.  If nothing turns up, then you will have to trouble-shoot to find the source (or sink, given that the offset seems to be negative) of the fault current.  Note that the inputs of the DMM ASIC are suspect due to possible internal failure of the chip.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Hydrawerk on May 20, 2016, 08:13:28 pm
At school I found an UT61E that has some strange behaviour in capacitance mode. When nothing is connected, there is no bargraph. When I short the input, a bargraph appears and starts moving while the displayed value is OL. This is weird.
Strange behaviour starts at 0:43.
https://www.youtube.com/watch?v=0fG7mhYjNag (https://www.youtube.com/watch?v=0fG7mhYjNag)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mariush on May 20, 2016, 08:24:23 pm
It's normal.

In resistance mode, you're measuring the resistance of the wire and the banana plugs, the value seems normal for that wire thickness.

When switching to capacitance you get the default base capacitance of around 2-300 nF.
Capacitance measurements are done by the multimeter by sending short pulses of voltage to capacitor and measuring the difference between pulses. A bigger capacitor charges slower.. With a short (the wire) you're basically ever so slightly heating up the wire with each pulse and the multimeter stays at OL (overload, or no capacitor) because there's no charge on the wire, no difference for the meter to measure.
 
You'll see the same behavior with a large capacitor (let's say 3300uF 16v) connected there, the bar at the bottom will pulsate several times at least before you get the value shown on screen.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Hydrawerk on May 20, 2016, 08:30:26 pm
The bargraph disappears and appears again. This is weird.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: nyarvin on July 16, 2016, 04:16:10 pm
One thing to note about the new PCB layout, as regards adding protection elements: there are four places to add MOVs (or gas discharge tubes), but the way they are connected is not simply as shunts to ground.  Instead, one of them shunts to ground and then the other three connect to it.  So if you just stick one-kilovolt MOVs in all of them, they may not fire until the input reaches two kilovolts.  Instead, for a kilovolt of protection, use 500V MOVs everywhere, or three one-kilovolt MOVs plus a jumper in the fourth place.

Also, besides those four places, there's another unpopulated space for a MOV near the current-measuring stuff.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on September 01, 2016, 01:07:59 am
I picked up a brand new UT61E.   It appears identical to the one 5KY had sent.   Metal can and all.   

So, what I would like to do if modify this meter with the MOVs people are recommending, or use the parts that are available in the one being supplied to Germany.   I will then retest it to failure and see if there are any improvements. 

Keep in mind the 61E and D never made it to the mini surge test.  They both failed ESD with that little grill starter.   
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: jarvis on September 01, 2016, 08:25:07 am
The bargraph disappears and appears again. This is weird.

The bar-graph is shown by the measurement time counting down for mF range of CAP.
It is indicated in datasheet of ES51922 chip.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MosherIV on September 01, 2016, 08:30:25 am
Hi

Quote
So, what I would like to do if modify this meter with the MOVs people are recommending, or use the parts that are available in the one being supplied to Germany.   I will then retest it to failure and see if there are any improvements.

Look at this thread
https://www.eevblog.com/forum/testgear/varistormov-for-ut61e/ (https://www.eevblog.com/forum/testgear/varistormov-for-ut61e/)

I have just got these
http://cpc.farnell.com/epcos/b72210s0381k101/varistor-40-0j-385vac/dp/RE03689 (http://cpc.farnell.com/epcos/b72210s0381k101/varistor-40-0j-385vac/dp/RE03689)
to fit in mine. Have not fitted them yet, I want to check the capacitance measurement before and after - I will only have access to a LCR bridge at the weekend to check the 1% caps, that I just bought, against the meter readings.

These
http://cpc.farnell.com/epcos/b72214s0321k101/varistor-84-0j-320vac/dp/RE03698 (http://cpc.farnell.com/epcos/b72214s0321k101/varistor-84-0j-320vac/dp/RE03698)
Will give you a lower clamp voltage but not give you the full 1000V DC spec
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on September 02, 2016, 01:59:22 am
Hey, I remember your other thread and was hoping you would have tried them out by now.  I'm in no rush so take your time and post your results on the capacitance.   Hard to believe it would be a problem as you zero it out anyway.     

Hi

Quote
So, what I would like to do if modify this meter with the MOVs people are recommending, or use the parts that are available in the one being supplied to Germany.   I will then retest it to failure and see if there are any improvements.

Look at this thread
https://www.eevblog.com/forum/testgear/varistormov-for-ut61e/ (https://www.eevblog.com/forum/testgear/varistormov-for-ut61e/)

I have just got these
http://cpc.farnell.com/epcos/b72210s0381k101/varistor-40-0j-385vac/dp/RE03689 (http://cpc.farnell.com/epcos/b72210s0381k101/varistor-40-0j-385vac/dp/RE03689)
to fit in mine. Have not fitted them yet, I want to check the capacitance measurement before and after - I will only have access to a LCR bridge at the weekend to check the 1% caps, that I just bought, against the meter readings.

These
http://cpc.farnell.com/epcos/b72214s0321k101/varistor-84-0j-320vac/dp/RE03698 (http://cpc.farnell.com/epcos/b72214s0321k101/varistor-84-0j-320vac/dp/RE03698)
Will give you a lower clamp voltage but not give you the full 1000V DC spec
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: exxocet on October 05, 2016, 09:16:28 am
Hey guys,
  I've got my UT61E back in 2010, way before it became the star of the affordable DMM show. :D  Gotta be one of the first PCB layouts, there were no EU versions back then. Input protection is really basic, no safe-cut board on the PTC, no resistor area shielding, but hey, it's a great DMM if you're not dealing with industrial voltages/currents, as most of us never do. It served me like a hero and it still works damn well, but... what's that bridge on capcitors C9a and C9b? Is this a soldering fault or it's the default design on this early PCB version?
  Maybe someone with a similar PCB would help with a picture of his own layout. Thank you.
 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on October 05, 2016, 05:34:34 pm
Hey guys,
  I've got my UT61E back in 2010, way before it became the star of the affordable DMM show. :D  Gotta be one of the first PCB layouts, there were no EU versions back then. Input protection is really basic, no safe-cut board on the PTC, no resistor area shielding, but hey, it's a great DMM if you're not dealing with industrial voltages/currents, as most of us never do. It served me like a hero and it still works damn well, but... what's that bridge on capcitors C9a and C9b? Is this a soldering fault or it's the default design on this early PCB version?
  Maybe someone with a similar PCB would help with a picture of his own layout. Thank you.
 

I would wager I could kill a brand new UT61E without anything more than the dry winter air,  the carpet in my office,  my metal desk and my hands.  Sounds real industrial.   :-DD   

My guess is C9a/b are in parallel and one is hand selected and soldered as a cheap way to trim this part of the circuit.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: exxocet on October 05, 2016, 06:02:25 pm
 
Quote

I would wager I could kill a brand new UT61E without anything more than the dry winter air,  the carpet in my office,  my metal desk and my hands.  Sounds real industrial.   :-DD   

My guess is C9a/b are in parallel and one is hand selected and soldered as a cheap way to trim this part of the circuit.

  Yeah, while all the other components look industrially soldered (you like that, ah? ;D ), it's always C9 that seems hand soldered. Badly soldered.
  PS: I've re-soldered those schmucks and C9a is in fact two capacitors, one on top of the other.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on October 05, 2016, 10:17:24 pm
I do like the 
Quote
it's a great DMM if you're not dealing with industrial voltages/currents, as most of us never do.
.    I understand that lack of robustness may be considered a desired trait as the meter being damaged easily provides the user with an indication that their meter was exposed to something that may cause it to fail later on.   For these people, it will be hard to beat the UNI-T brand!!   :-DD

So three capacitors in parallel?   This sort of makes sense.  Labor is cheap.  Start with the large part, add trimmer one, then a fine trim.  Does not look great but gets the job done. 




Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: exxocet on October 06, 2016, 06:26:11 am
I do like the 
Quote
it's a great DMM if you're not dealing with industrial voltages/currents, as most of us never do.
.    I understand that lack of robustness may be considered a desired trait as the meter being damaged easily provides the user with an indication that their meter was exposed to something that may cause it to fail later on.   For these people, it will be hard to beat the UNI-T brand!!   :-DD

So three capacitors in parallel?   This sort of makes sense.  Labor is cheap.  Start with the large part, add trimmer one, then a fine trim.  Does not look great but gets the job done.

  A DMM that pass your test (by the way, awesome job) it's great DMM? No, it's safe DMM. It plays well outside of it's specs. That safe meter may measure 10.7v on a 10v reference source and that makes it a shit DMM, even if it's safe. Why? Simply because it's not doing what it was designed to do.
  UT61E it's a $50 meter that does most of what $500 Fluke does. Now I know that Americans have a fetish for Fluke, but there are hobbyist that don't afford to pay $500 for a DMM, while they don't make any money from it. Oh, you run a business or your incoming allows? Go for Fluke, it's a reliable and rock solid meter. But I tell you, it's still way overpriced. Cool PCB alignment, fine soldering and adequate V/A protection still don't make for 10 times the price of the Chinese meter.

  Anyway, you're right here, cheap DMM shouln't be cheap on security, especially on input protection. I mean, it's so easy to design a proper one and won't add more that $0.5 on the  production cost, but what you gonna do... guess that's the Shenzhen way.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ProBang2 on October 06, 2016, 06:51:46 am
Now I know that Americans have a fetish for Fluke

Honestly, you can´t joeqsmith call a fanboy of Fluke. At least not for the 87V.
He obviously prefer the Brymen869. A DMM outperforms the Fluke87V in CAT-Ratings (Cat IV 1000V versus CAT IV 600V) and some other functions for half the price...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: exxocet on October 06, 2016, 11:23:42 am
  I'm not talking specifically about joeqsmith. He is a pro, he knows his equipment and use what's the most efficient for his job. Doesn't really matter if the DMM costs $200 or $500 as long as it's a tool to perform your profession.
  I'm talking about the joe-q-average, that use a DMM for hobby or occasional works. You don't make money from using that DMM, you pay money to enjoy your hobby. Why would you pay $500 for a tool that should cost at most $300, including the "Fluke brand name aura"? You're right, it's twice as much as it should be. Anyway, guess I'm offtopic, back to our little chinese friend.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on October 06, 2016, 01:17:21 pm
  A DMM that pass your test (by the way, awesome job) it's great DMM? No, it's safe DMM. It plays well outside of it's specs.

  :horse:  :-DD  Dead horse with and a parrot would have been my choice.   I wonder how much of the confusion comes from the language.  So to be clear, you feel if a meter survives with transient that has 10 to 20 Joules available that means it's safe?

Pretty much all the meters I look at are CAT III 600V rated per IEC 61010.  That's the spec.  Now what that means as far as their ability to survive the transients I supply is up for grabs. 

That safe meter may measure 10.7v on a 10v reference source and that makes it a shit DMM, even if it's safe. Why? Simply because it's not doing what it was designed to do.

Yea, if you bought a meter that was spec'ed this loose, that's on you.  If the meter is outside it's spec'ed accuracy and it was shipped to you this way, you may want to return it.   Most of the meters I have looked at work when they arrive and are in spec.  The last CEM I looked at and the free meters we get from Harbor Freight were dead out of the box.  Pretty rare.   

UT61E it's a $50 meter that does most of what $500 Fluke does. Now I know that Americans have a fetish for Fluke, but there are hobbyist that don't afford to pay $500 for a DMM, while they don't make any money from it.
Oh, you run a business or your incoming allows? Go for Fluke, it's a reliable and rock solid meter. But I tell you, it's still way overpriced. Cool PCB alignment, fine soldering and adequate V/A protection still don't make for 10 times the price of the Chinese meter.

  Anyway, you're right here, cheap DMM shouln't be cheap on security, especially on input protection. I mean, it's so easy to design a proper one and won't add more that $0.5 on the  production cost, but what you gonna do... guess that's the Shenzhen way.

The UT61E is pretty low end but you are right, the Fluke 101 does not have a backlight just like the 61E.   :-DD  And sure, you touch it wrong and static zap it, it may very well suffer permanent damage.  And sure it's not certified to meet the safety or EMC standards.   Sure, it is supplied with crap fuses....

It would be interesting to see some data showing handheld meter purchases in the USA by OEM and cost.  I really have no idea.  I doubt Fluke is the brand that the average person finds at the hardware store. 
 
Again, for my normal use where I need a handheld I still use $50 meters.  But my $50 meter can take some basic ESD.  I also have a backlight, which I use.   This is mostly for working on cars, bikes and such.  So I just don't need much for a meter. 

I really don't know what it would cost UNI-T to roll a better version of the 61E that passes both the EMC and safety standards and maybe adds a backlight.  I did not have a 61E at the time I did the temperature drift study but I hear it is pretty bad.  Maybe improve this as well.    The cost of scrap, new layout, parts, setup, testing, certification... How many they sell...   Yea, I have no idea.  The GS version looks to me more like $20 - $40 higher, not $0.50.     



Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: igi on October 12, 2016, 08:38:13 am
Guys, I killed my brand new UT-61E. Tried to measure voltage on a microwave transformer and device turned off forever. Yes, that was dumb, I know. But any chance to get it back? Can't justify myself to throw new shiny device into a trash bin. Nothing happens when I rotate the dial, screen remains off. Battery is fine. I see no visible damage to internals. The only thing happening inside is W1 (linear voltage regulator 7201U30 is becoming warm). I desoldered and checked this LDO and it works fine itself. So i guess there is some kind of short circuit somewhere down the road. Any hope it is not a main chip? Should I check something else? The schematics of the device is a bit too complex for me, I am a newbie. Thanks!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: setq on October 12, 2016, 10:22:58 am
Doh. I think that'd blow up a lot of things. I'd chuck it and buy another one.

As for safety, I've got a UT61E. It occasionally gets stuck across the mains. If it blows up, it blows up. I'll just buy another one.  I'd have to buy 8 of them before I caught up with a Fluke's pricing. If I'm going to kill myself it is more likely due to human error, probing errors etc than anything to do with the meter exploding. Daily use it sees 5mV-300v DC.

However going back not so far ago, the status quo of meters was far more dangerous than a UT61E. Even a relatively recent 1980s FET based meter from a respectable brand I saw had a negative terminal connected to the chassis and a non-earthed supply. Stuff that across the mains and things get interesting.

Most of the fluff that Fluke point out about safety isn't relevant or useful to the average user.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MosherIV on October 12, 2016, 01:41:14 pm
Quote
Guys, I killed my brand new UT-61E. Tried to measure voltage on a microwave transformer and device turned off forever. Yes, that was dumb, I know. But any chance to get it back? Nothing happens when I rotate the dial, screen remains off. Battery is fine. I see no visible damage to internals. The only thing happening inside is W1 (linear voltage regulator 7201U30 is becoming warm). I desoldered and checked this LDO and it works fine itself. So i guess there is some kind of short circuit somewhere down the road. Any hope it is not a main chip? Should I check something else? The schematics of the device is a bit too complex for me, I am a newbie. Thanks!
It sounds like you have blown the main chip. Without the MOVs in place there was no chance of the input protection stopping KV, even with them fitted joeqsmith proved they can be inadequate.
The main chip is not obtainable, the chip manufacturer does not sell on the open market.

Salvage what you can and get a new DMM. Most DMM are not capable of measuring thousands of V (KV) - do no attempt it again unless you like spending money on DMMs  ::)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on October 12, 2016, 10:10:01 pm
Can't justify myself to throw new shiny device into a trash bin.

I wouldn't.  Driving over it, throwing it out the car window, dropping it from 3 or 4 stories and shooting it with an arrow are all little overdone.  Make a video of what you come up with.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Hydrawerk on October 16, 2016, 11:12:03 pm
Tried to measure voltage on a microwave transformer and device turned off forever.
I think that even Brymen BM869 will be damaged by 2000V 500mA or so. Hardly any DMM can handle 2000V for a long time.  :(
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on October 21, 2016, 09:10:59 am
My old multimeter has finally given in and it seems the UT61E is the way to go (this is for hobby use -mostly measuring low voltage stuff and the occasional AC household (230V) measurements).

Have the safety issues been resolved with the currently available UT61E?
Where's the best place to order it from these days?
Apparently, the "GS" European version isn't available from the many Chinese low cost sources but through various German dealers such as Pinsonne-elektronik (75 Euros) (http://www.pinsonne-elektronik.de/pi2/pd58.html). But confusingly many Chinese dealers sometimes show a mix of the "GS" and "China" version of the unit along with USB and serial cables, and if you ask them about it they seem to tell you what they think you want to hear and really have no clue other than to shift as many cardboard boxes around as they can!

So, if I don't want to pay the much higher "GS version" costs, where's a good place to get it?
(of course, if some low cost Chinese dealer does have the actual "GS" version for sale cheaper than buying it from a dealer in Europe I'll definitely be going for that instead).

And does the current version now come with a USB cable or is this also a random thing?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Loboscope on October 21, 2016, 10:12:10 am
I bought my UT61E from "pinsonne-elektronik.de", it was shipped immediately. It came with USB-Connection and of course it was the official "GS"-version.
So I can recommend "pinsonne-elektronik".
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on October 21, 2016, 11:02:38 am
Sounds like a good place to order from, even though the price will be higher than with the Chinese version.
Unfortunately, although Pinsonne-elektronik will send to Sweden and Denmark, Norway isn't listed  :(
I'll keep on searching, and if the total price will be too high I'll probably go for the Chinese version instead -suggestions to where I should get it from?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MosherIV on October 21, 2016, 11:05:54 am
I bought mine from Amazon. They have a 'market place' so there were 4 or 5 vendors offering UT61E.
The advantage of Amazon is that they provide the seller vetting and should sort out any disputes with the seller,
I have not had any trouble with my UT61E (hopefully never will).
I do not remember which vendor I chose.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: setq on October 21, 2016, 12:22:13 pm
For ref, mine was seller "emma2103dw" £35.99 inc delivery. Drop shipping op. Arrived in 3 days RM 2nd class no problems at all.

Gubbins and input protection in my variant:

(http://i.imgur.com/VZN9VC9.jpg)

No problems either.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on October 23, 2016, 02:25:09 am
Have the safety issues been resolved with the currently available UT61E?
Where's the best place to order it from these days?
Apparently, the "GS" European version isn't available from the many Chinese low cost sources but through various German dealers such as
....
So, if I don't want to pay the much higher "GS version" costs, where's a good place to get it?
(of course, if some low cost Chinese dealer does have the actual "GS" version for sale cheaper than buying it from a dealer in Europe I'll definitely be going for that instead).
....

I would assume that the GS would be similar to UL, CSA and others.   There does appear to be some differences in the hardware between the standard and the GS ones.   They come with the MOVs, larger HRC fuses and possibly different PTCs.  I assume the GS mark does not mean that the meter meets EMC standards, only the safety.   I doubt the GS would survive the ESD standard.   But it is a UNI-T.   

Mine after changing to larger SIBA fuses, adding MOVs, changing out 5mm PTCs, cutting some traces and adding a few resistors, swapping out the crappy split connectors, changing out one of the clamps with TVSs and then applying dope over the HV areas.   If that was not enough, then adding an adaptive backlight to the thing because it's too cheap a meter to include it. 

While I do not consider this meter safe by any means and would NEVER suggest anyone modify their meter in any way, it is now very robust!   If you want a nice robust meter, get Dave's little Brymen.  That meter even comes with a back light!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on October 23, 2016, 09:51:59 am
For ref, mine was seller "emma2103dw" £35.99 inc delivery. Drop shipping op. Arrived in 3 days RM 2nd class no problems at all.

Is this on eBay, Amazon or some other place? I haven't been able to find it.
It appears that I have to pay quite a lot more than that if I want the "GS" version, so in that case I might as well buy a more expensive meter, buy a UT61D locally (they're about US$ 75/EUR 74/GBP 65) which is GS marked and comes with both USB and serial cables (which when I think about it really doesn't matter anyway as I'm on a Mac and all that software is Windows only).
But that's the Chinese (non-GS) version you have there, right?
And as far as I know, none of the Chinese versions come with USB cables -but if I'm not mistaken the actual meter is the same, and it's just a matter of attaching a USB cable or serial cable, right? There's no actual "USB version" or "serial version" of the multimeter, is there?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on October 23, 2016, 09:56:38 am
While I do not consider this meter safe by any means and would NEVER suggest anyone modify their meter in any way, it is now very robust!   If you want a nice robust meter, get Dave's little Brymen.  That meter even comes with a back light!

Actually, without the in-depth knowledge you and others here seem to have, I think I might just risk making the multimeter more unsafe by trying to modify it, and would rather not.
So in conclusion, would you say that the "Chinese" version of the UT61E is unsafe to use (it won't be used for higher voltages than household AC 230V) as it is, and if I want a safe UT61E I would have to go for the "European GS-marked" version?

Which Brymen model are you referring to and how does it compare to the UT61E?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MosherIV on October 23, 2016, 10:53:01 am
Quote
as far as I know, none of the Chinese versions come with USB cables -but if I'm not mistaken the actual meter is the same, and it's just a matter of attaching a USB cable or serial cable, right? There's no actual "USB version" or "serial version" of the multimeter, is there?
Yes correct, the meter just outputs a serial stream. Then there is an optical infra red to seril or usb adapter.
I think all UT61E come with the infra red to serial adapter only.
Some chinese retailers MAY throw in a cheat IR to usb adapter but dont quote me on that.

Quote
So in conclusion, would you say that the "Chinese" version of the UT61E is unsafe to use (it won't be used for higher voltages than household AC 230V) as it is, and if I want a safe UT61E I would have to go for the "European GS-marked" version?
Basically correct. None of the chinese versions have enough protection circuitry to pass the GS safety tests (bear in mind the test may damage the meter, the idea of the test is to prove the meter will not injure)
They can measure high voltages and will PROBABLY NOT blow up. There is a chance that it will if there is a surge. Think about it like crossing the road, most of the time you will cross and nothing will happen BUT there may be the one occaision where you cross and get knocked down by a bus.

If you want a general purpose meter for all uses, including safe to use on high volts, yes look at another meter.
If you want a cheap meter with high resolution and accuracy AND only want to use it for low voltage (less than 50V) then the UT61E is the meter to get
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on October 23, 2016, 06:24:54 pm
Nice and clear summary!  :)
I will use it mainly for low voltage (less than 50V), but do need to check the occasional AC household voltage, and risking a shock because of a poorly made meter isn't too tempting.

Which alternative meter would you recommend with similar features to the UT61E?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MosherIV on October 23, 2016, 07:41:14 pm
Quote
Which alternative meter would you recommend with similar features to the UT61E?
Unfortunately, there nothing around with similar features in the same price range  :(

I think the next DMM with similar features will be one of the higher end Brymen meters, eg BM867

Then you are into Flukes and Keysights, Fluke 87 or Keysight U1272. These are very expensive !

Have you thought about getting 2 DMMs?
Then you can get the UT61E and another which is safe for mains eg Daves BM235
It is a good idea to have multiple meters, eg check strange readings with 2nd meter
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: omgfire on October 23, 2016, 08:44:47 pm
Quote
Which alternative meter would you recommend with similar features to the UT61E?
Unfortunately, there nothing around with similar features in the same price range  :(

I think the next DMM with similar features will be one of the higher end Brymen meters, eg BM867
Isn't DER EE DE-5203 pretty much UT61E done right for twice the price? Temperature, backlight, max-min, LPF.
https://www.deree.com.tw/de-5203-digital-multimeter-de-5203-rms.html (https://www.deree.com.tw/de-5203-digital-multimeter-de-5203-rms.html)
https://www.eevblog.com/forum/testgear/der-ee-de-5203-first-impressions/ (https://www.eevblog.com/forum/testgear/der-ee-de-5203-first-impressions/)
http://www.pcstore.com.tw/adm/psearch.htm?store_k_word=REUtNTIwMw==&slt_k_option=1 (http://www.pcstore.com.tw/adm/psearch.htm?store_k_word=REUtNTIwMw==&slt_k_option=1)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: setq on October 23, 2016, 08:52:52 pm
Isn't DER EE DE-5203 pretty much UT61E done right for twice the price? Temperature, backlight, max-min, LPF.

No. I use the frequency counter on my UT61E a lot. It's actually good to about 30MHz if you buffer it with something with some reverse isolation.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: omgfire on October 23, 2016, 09:01:57 pm
No. I use the frequency counter on my UT61E a lot.
Oh, I missed that. Thanks.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on October 23, 2016, 09:30:49 pm
Have you thought about getting 2 DMMs?
Then you can get the UT61E and another which is safe for mains eg Daves BM235
It is a good idea to have multiple meters, eg check strange readings with 2nd meter

Yes, that's certainly an option. Or a good and safety-approved "voltage tester" for the simple AC household voltage stuff (checking if a connection is live or not).
I do prefer having "all in one" type devices though (gear tends to pile up), so a multimeter with all the features I need including good safety specs would be ideal.

I had a look at Amprobe's offerings (AM-510, 520, 530, 540 etc.) again (from what I've heard they're the budget alternatives from Fluke) as I expect them to at least meet safety standards, but from what I've read in these forums they're a mixed bag, so I really don't know.

The big question is what kind of features am I looking for?
I'm not a very advanced electronics hobbyist ("intermediate" i would say) and besides the usual voltage/current/resistance/capacitance I need a good, responsive continuity tester, the ability to test LEDs and a frequency counter (not sure about the range though, but for audio and some digital electronics). It doesn't have to be super accurate (as in a voltage reading of e.g. 1.203785198 V), but hopefully not something that drifts too much within a year or too (I hear calibration is pretty expensive, not worth it for meters in this price range) and built well (I prefer paying a bit more for something that lasts than going for bargain basement stuff, but then again not pay a whole lot for features I don't need).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: MosherIV on October 23, 2016, 09:49:44 pm
Quote
The big question is what kind of features am I looking for?
I'm not a very advanced electronics hobbyist ("intermediate" i would say) and besides the usual voltage/current/resistance/capacitance I need a good, responsive continuity tester, the ability to test LEDs and a frequency counter (not sure about the range though, but for audio and some digital electronics). It doesn't have to be super accurate (as in 1.203785198 V), but hopefully not something that drifts too much within a year or too (I hear calibration is pretty expensive, not worth it for meters in this price range) and built well (I prefer paying a bit more for something that lasts than going for bargain basement stuff, but then again not pay a whole lot for features I don't need).
If you only want 1 meter and it must have features, the Bryman B867 is probably the best fit though I do not know what freq range it has. I do not have any Bryman DMMs myself but everyone else in this forum speak highly of them.
It is 3/4 times the price of the UT61E. The appeal of the UT61E is the price verses the resolution and accuracy.

Write down what you are looking for in a DMM, rank them in order. This will help you decide which meter best fits your needs.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Loboscope on October 24, 2016, 08:44:42 am
If you only want to check "simple AC household voltage stuff (checking if a connection is live or not)", you should use an UT61E (the GS-version) without risk. The "CAT"-categories will have a meaning* and with "simple AC household voltage stuff (checking if a connection is live or not)" you should stay completely in the CAT-III environment. But you should not test at the busbar and never at all behind it with the 61E!

But if you feel unsafe with the UT61E (GS), I could recommend the Benning-testers for electricians for testing mains. For example the more simple but very useful "Benning Dutest  050156" (but it is also only rated CAT-III 300V) or the more safe "Benning Duspol 050261" which is also not expensive but rated CAT-III 1000V / CAT-IV 600V. With a Duspol you can also test at the busbar.
Bennig Duspol is a kind of ´standard´-meter for electricians and all I can say is, that you can trust their CAT-safety-specifications.

*) A good description can be found here: http://www.metrel.si/dl?d=PDF_dokumentacija/White_papers/Ang/White_paper_Overvoltages_and_high_current_breakdowns.pdf (http://www.metrel.si/dl?d=PDF_dokumentacija/White_papers/Ang/White_paper_Overvoltages_and_high_current_breakdowns.pdf)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on October 26, 2016, 08:56:01 pm
I'll only need to check if a household connection is live or not (max. 230V AC) and didn't even know what a busbar was until I looked it up  ???

I finally found a GS version of the UT61E which can be delivered to my country, by going to Reichelt (http://www.reichelt.de/) in Germany. The total price will be around EUR 112/US$ 125 with shipping taxes etc., so not exactly cheap. But as has been said here earlier there really aren't any meters in this price range (or even quite a bit higher) with the same features and that the GS version as least should be a safe bet when it comes to household voltages, right?
I might just go for it if that's the case and I won't need a separate meter/probe for those instances when I need to check for a live AC household voltage.
Apparently even the Amprobe meters are quite similar to the Uni-T ones inside, but have poorer features including a slow continuity test response.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on October 30, 2016, 04:32:33 pm
While I do not consider this meter safe by any means and would NEVER suggest anyone modify their meter in any way, it is now very robust!   If you want a nice robust meter, get Dave's little Brymen.  That meter even comes with a back light!

Actually, without the in-depth knowledge you and others here seem to have, I think I might just risk making the multimeter more unsafe by trying to modify it, and would rather not.
So in conclusion, would you say that the "Chinese" version of the UT61E is unsafe to use (it won't be used for higher voltages than household AC 230V) as it is, and if I want a safe UT61E I would have to go for the "European GS-marked" version?

Which Brymen model are you referring to and how does it compare to the UT61E?

I would dare say that any time any of us make changes to a meter we have no idea how we effect the safety rating.   This includes me.

I would have liked to run the GS version but it was hard to find.  I assume that it is required to pass some sort of independent safety test to have the GS mark but I really don't know. I do doubt it would pass the EMC standards for ESD but that's not a safety requirement.   

I was referring to Dave's rebranded BM235.  If I were to pick between the Fluke 115, the HIOKI DT4253 and the BM235, I would go with the 235.  The cost is a wash and at least from the tests I ran, the 235 is electrically very robust.   
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: snovotill on November 12, 2016, 06:44:04 am
New updated UT61E schematic is available at "ESI Service Info" website!
Get the CORRECTED version. It shows new protective circuitry, though SG1 does not show a voltage rating.
Oddly enough there are two components labelled SG4 and this corresponds with the silkscreen!
http://www.eserviceinfo.com/downloadsm/68103/UNI-T_UT61E.html (http://www.eserviceinfo.com/downloadsm/68103/UNI-T_UT61E.html)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: WackyGerman on November 12, 2016, 07:55:26 am
I'll only need to check if a household connection is live or not (max. 230V AC) and didn't even know what a busbar was until I looked it up  ???

In this case it is better to use a voltage tester such like Benning Duspol Series or Fluke T Series . I would never ever use a multimeter even not my Metrahit 29 S or Agilent U1241 B . A voltage tester shows you if the circuit is live or not directly and not weird digits like on multimeters with high input resistance . The VDE rules pretends you to use a voltage tester on 0 V measurements here in Germany
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on November 12, 2016, 11:43:50 am
The Benning Duspol series is quite expensive here, while the Fluke T-90 is a little lower, but still a bit costly for something I'll do quite seldom.

Interestingly Fluke also has a couple of "non-contact" voltage testers which are more affordable: the Fluke 2AC (http://www.fluke.com/fluke/m2en/electrical-test-tools/electrical-testers/2ac.htm?PID=70668) and Fluke LVD2 (http://www.fluke.com/fluke/m2en/accessories/lights/lvd2.htm?PID=56369) (see attached photos).
Are these suitable/safe for checking if mains power is on or off at an AC-outlet, a lamp socket etc?
Of course Uni-T also has a few contactless voltage testers, but if I'm aiming for safety it appears from all these postings that it would just be lucky guessing...
However, any of those voltage testers must be a million times safer than the mains testing neon lamp screwdriver I've used a few times. I just learnt that although it's legally sold it's very dangerous to use, so I'll be getting rid of it right away:
Youtube: Dangerous Device - Neon Mains Testing Screwdriver (https://youtu.be/wLAJ-keFmpk)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Loboscope on November 12, 2016, 12:51:23 pm
I have a Fluke "1 AC-II Volt Alert" [http://www.fluke.com/fluke/dede/elektrische-messgerate/spannungsprufer/tester-fur-elektrotechnik/spannungsprufer/fluke-1ac-ii.htm?pid=56048] and it works fine, simple and reliable. Contcatless testing will always be safer for sure. But the range of the Fluke Volt Alerts will only begin at 90-200 Volt depending on the model so there could be a voltage of 80 Volt for example which will not be indicated but will also be dangerous!
But if the Voltage Alert will not indicate some voltage and you will have a reasonable suspicion there should be som -lower- voltage, you can take the UT61E for measuring this lower voltage. Voltages less than 90 Volt should be no problem for the UNI-T.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on November 12, 2016, 12:59:08 pm
Ah! Thanks for pointing that out.
So in that case the Fluke T-series will also detect voltages lower than 80V and in some sense be safer than the contactless ones. I like "all in one" solutions, so perhaps a contactless one which also goes down to lower than 80V would be ideal. Maybe some of them have a sensitivity switch: if it doesn't detect anything above 80V for instance, a switch checking for lower voltages will allow another check before ensuring that there's no voltage present.
Many years ago I remember the German company Steinel made quality voltage testers. I see they're still around, and there are also similar (but different branded) testers with an LED for each voltage range (i.e. AC 12, 50, 110, 220V etc.). At least they check voltages lower than 80V but aren't contactless.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: WackyGerman on November 12, 2016, 02:38:07 pm
Yes my Fluke T 150 measures from 6V to 690V AC and DC , also nice for 12 V halogen lamp jobs . The T 90 measures fro 12 V to 690 V . Alternatively you could buy the voltage tester Uni-T 15 C which costs roundabout 40 € , it also measures from 12 V to 690 V AC and DC
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on November 13, 2016, 09:15:23 pm
I will most likely save up a Fluke voltage tester of some sort the next time I need something like that. The contactless ones appear very handy and practical (and relatively affordable), but I'm put off by them not measuring below a certain relatively high voltage, so I might splurge and buy a Fluke T-90 (around € 55/US$ 60 here). Uni-T has their UT-18A (around € 38/US$ 42) and the contactless UT-11A (around € 14/US$ 15) but that would be kind of ironic when I'm not going to use a UT-61E for AC measuring because its questionable safety design. Too bad because their contactless UT-11A actually measures from AC 50V.

Quote
New updated UT61E schematic is available at "ESI Service Info" website!
Get the CORRECTED version. It shows new protective circuitry, though SG1 does not show a voltage rating.

I haven't gotten around to it yet, but I plan to buy the GS version of the UT-61E from Reichelt in Germany (https://www.reichelt.de/UT-61E/3/index.html?ACTION=3&LA=446&ARTICLE=97151&artnr=UT+61E). They confirmed that indeed, they sell the GS approved type.
So how can I ensure I get the corrected version? Is it a matter of asking for one manufactured after a certain date or batch, or were they corrected several years ago so it's likely I get a corrected version anyway?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Loboscope on November 14, 2016, 09:36:28 am
The "GS"-version must have the "GS"-label. You can see it here on the picture just above the "Hold"-button: http://www.pinsonne-elektronik.de/pi2/pd58.html (http://www.pinsonne-elektronik.de/pi2/pd58.html)
And it is also rated to a lower voltage and this is printed just beneath the connector-sockets. The picture on the reichelt-page indeed shows the wrong version. But I would trust reichelt if they confirm they will deliver the GS-version (but they should adjust the product page accordingly). I bought my UT-61E one month ago at pinsonne-elektronik and there was no problem, it is the GS-model as described.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on November 14, 2016, 10:22:18 am
Yes, they should indeed update the photo which doesn't show it to be GS-approved.
I contacted Reichelt and they replied saying that their version is GS-approved as shown in the German manual linked from their site (https://www.reichelt.de/index.html?ACTION=7&LA=3&OPEN=0&INDEX=0&FILENAME=D100%252F2013-07-31_UT61A-E.pdf).
I noticed that the specs on the Reichelt page says "Safety: Cat II 600 V, CAT III 300 V". I suppose these differ from the "Chinese" version.
I'd order it from Pinsonne if I could, but they don't deliver to Norway.

About getting the "Corrected" version of the UT-61E as pointed out by Snovotill: perhaps this only concerns the "Chinese" version as the "European" GS version is already safe (or should I say "a little safer"?) ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: mac.6 on November 14, 2016, 10:58:22 am
Hello All,

I have an UT-61E clone (voltcraft) that got its LCD screen broken. It seems still functional anyway.
Does anybody knows a spare part vendor?
It will be a pity to throw it away or recycle it as a datalogger...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: snovotill on November 15, 2016, 06:55:28 am
Quote
About getting the "Corrected" version of the UT-61E as pointed out by Snovotill: perhaps this only concerns the "Chinese" version as the "European" GS version is already safe (or should I say "a little safer"?) ?
The Chinese version is what I have and it has no MOV's installed in the "SGx" positions. Regarding the "uncorrected" schematic: it's just plain wrong so please ignore it and download the "corrected" one.

There are four MOV's installed in the GS version as per pictures in other posts, but the duplicate instance of SG4 above the COM jack is unpopulated and is a smaller part, so likely intended for a true spark gap.

SG2, SG3, and SG4 in the GS version have part number ZOV 07D-751K per photos in other posts and this decodes as follows:
 ZOV = Zinc Oxide Varistor (plain vanilla MOV)
 07D = 7mm diameter disk (so about 50 Joules)
 751 = 750V (so 460VAC or 615VDC max operating)
 K = 10% tolerance on the rated voltage spec.

HOWEVER there is no part number listed for SG1 on the schematic, so I wonder if someone with the GS version could kindly have a look inside their unit and report back to the forum with the part number for SG1 at left of the PCB. A close-up photo of the smiling MOV could be nice too :D.

Schematic reference: http://www.eserviceinfo.com/downloadsm/68103/UNI-T_UT61E.html (http://www.eserviceinfo.com/downloadsm/68103/UNI-T_UT61E.html)

thanks ;)
   
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on December 03, 2016, 05:08:13 pm
A few higher res pictures of 61E after replacing both fuses, fuse holders, PTCs, adding MOVs, cutting the traces for adding the resistors, adding the adaptive backlight.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on December 03, 2016, 05:12:56 pm
 Also shown is the temperature compensation that I came up with after swapping all the parts in the reference circuit.  This was just a BAV199 and a 6.65K in series across C17.  Note that the original meter came with a tant and I had replaced with a ceramic. 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on December 19, 2016, 05:29:15 pm
Quote
A few higher res pictures of 61E after replacing both fuses, fuse holders, PTCs, adding MOVs, cutting the traces for adding the resistors, adding the adaptive backlight.

:-+
Does it pass the torture tests?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hgg on December 19, 2016, 05:31:28 pm
Just saw at Uni-T website that they list the UT61E with a backlight.
http://www.uni-trend.com/productsdetail2.aspx?ProductsID=1174&ProductsCateId=909&CateId=909 (http://www.uni-trend.com/productsdetail2.aspx?ProductsID=1174&ProductsCateId=909&CateId=909)

Is that true?
Does anybody have any new unit that has the backlight?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on December 19, 2016, 07:39:38 pm
I've just received a few days ago a GS approved UT61E which I bought from Reichelt in Germany (https://www.reichelt.de/UT-61E/3/index.html?ACTION=3&LA=446&ARTICLE=97151&artnr=UT+61E). I assume it's new though I haven't yet had the time to open it up and look inside. There's no mention of any LCD backlight anywhere, none of the two buttons (yellow and blue) nor any other button has so far lit the LCD, so I'm guessing this is an error at their website.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: PedroDaGr8 on December 19, 2016, 09:55:40 pm
I've just received a few days ago a GS approved UT61E which I bought from Reichelt in Germany (https://www.reichelt.de/UT-61E/3/index.html?ACTION=3&LA=446&ARTICLE=97151&artnr=UT+61E). I assume it's new though I haven't yet had the time to open it up and look inside. There's no mention of any LCD backlight anywhere, none of the two buttons (yellow and blue) nor any other button has so far lit the LCD, so I'm guessing this is an error at their website.

That is correct, no backlight on the UT61E. Though it can be added in a variety of ways, many of which are covered on this forum.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on December 20, 2016, 03:09:43 am
Quote
A few higher res pictures of 61E after replacing both fuses, fuse holders, PTCs, adding MOVs, cutting the traces for adding the resistors, adding the adaptive backlight.

:-+
Does it pass the torture tests?


These where the four videos I made showing mods I made to the front end along with testing, adding an adaptive backlight and finally temperature compensating it.  The spreadsheet comparing it against all the other meters I have looked at may be found here:

https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/ (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/)

https://www.youtube.com/watch?v=cMutvk_6xhY (https://www.youtube.com/watch?v=cMutvk_6xhY)

https://www.youtube.com/watch?v=d6LTsaOqk30 (https://www.youtube.com/watch?v=d6LTsaOqk30)

https://www.youtube.com/watch?v=S36LfKmSjKw (https://www.youtube.com/watch?v=S36LfKmSjKw)

https://www.youtube.com/watch?v=0ObW8AA42OY (https://www.youtube.com/watch?v=0ObW8AA42OY)

https://www.youtube.com/watch?v=RRhFYERTSxY (https://www.youtube.com/watch?v=RRhFYERTSxY)

https://www.youtube.com/watch?v=ns02v6ebCGU (https://www.youtube.com/watch?v=ns02v6ebCGU)

https://www.youtube.com/watch?v=7ivcPLOOACg (https://www.youtube.com/watch?v=7ivcPLOOACg)

https://www.youtube.com/watch?v=14eHpHQxm54 (https://www.youtube.com/watch?v=14eHpHQxm54)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sdttn on January 21, 2017, 01:13:23 pm
Hello,
I edited the first message. added pictures again. imageshack f.ed up my acount.
I am proud of this topic.  :D

I dont know if it is mentioned before i realized that you can keep the dmm always in display check (all segments lighting up) mode.
If you push and hold "HOLD" button while cranking the knob to any range and wait for 4 sec. to relaese the hold button it will stay in display check mode until you press the hold button again or restart the dmm.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: KuroZ on February 14, 2017, 08:20:42 pm
Just received. Dates to 10 August 2016.

http://yakumo.euamo.moe/temp/ut61e/00.jpg (http://yakumo.euamo.moe/temp/ut61e/00.jpg)
http://yakumo.euamo.moe/temp/ut61e/01.jpg (http://yakumo.euamo.moe/temp/ut61e/01.jpg)
http://yakumo.euamo.moe/temp/ut61e/02.jpg (http://yakumo.euamo.moe/temp/ut61e/02.jpg)
http://yakumo.euamo.moe/temp/ut61e/03.jpg (http://yakumo.euamo.moe/temp/ut61e/03.jpg)
http://yakumo.euamo.moe/temp/ut61e/04.jpg (http://yakumo.euamo.moe/temp/ut61e/04.jpg)
http://yakumo.euamo.moe/temp/ut61e/05.jpg (http://yakumo.euamo.moe/temp/ut61e/05.jpg)
http://yakumo.euamo.moe/temp/ut61e/06.jpg (http://yakumo.euamo.moe/temp/ut61e/06.jpg)
http://yakumo.euamo.moe/temp/ut61e/07.jpg (http://yakumo.euamo.moe/temp/ut61e/07.jpg)
http://yakumo.euamo.moe/temp/ut61e/08.jpg (http://yakumo.euamo.moe/temp/ut61e/08.jpg)
http://yakumo.euamo.moe/temp/ut61e/09.jpg (http://yakumo.euamo.moe/temp/ut61e/09.jpg)

It seems they didn't piggyback the capacitors.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on April 07, 2017, 08:21:37 am
Where can we find a full/complete API description?
Has it been made publicly available as PDF or HTML download?

 :-//
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on April 09, 2017, 05:56:52 pm
In Nov 2016, I had measured the temperature drift of my new UT61E and made a video were I compensated it.  I had also changed out the one trimmer pot.  Someone had asked about long term drift and I mentioned I would start collecting some data from mine.  It sounds like some people are seeing a lot of drift.  I can't help but wonder if this is operator or the meter.   

Anyway, here is some data from my UT61E after the temperature compensation taken on 11-21-16:
1mV: 1.02
1V: 1.0001
10V: 10.002
1nF: 1.003

I have had the meter apart a few times since then to make other modifications to it including the larger shunt for measuring 20A and attempting to improve the burden voltage in the uA range.  However, I have been careful not to adjust the trimmers that would effect this little study. 

You can see the in the mV range the meter appears to have a change of 30uV.  However, it's way to small of a change to hang my hat on and way too little time has passed.   I would expect the meter would be fairly stable.  Maybe people are using an unstable source to look at drift? 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on May 25, 2017, 03:52:16 pm
Hi guys, i am not sure if this piece of interesting information is known. It was news to me:

There is yet another PC logging software which has official (commercial) support for UT61E. It is developed by geman compani called ABACOM , and it is sold through various renowned geman electronics retailers. The software is called

ABACOM REALVIEW 3.0

You can download the latest Update (from 2015 afaik) for free from:
http://www.abacom-online.de/html/downloads.html (http://www.abacom-online.de/html/downloads.html)

(https://abload.de/img/realviewyesge.png)

It is pretty good and advanced, more professional than ultradmm.com . Please share in this thread which logging software you like best for UT61E. Either software does the job and delivers an exported data file which can be imported to Excel. So it doesn't really matter which software one uses for the logging and real-time plotting. It is matter of taste and preference.

With Realview 3.0 you got a very serious piece of software, professional and commercial. If you don't like freeware.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ansic on May 25, 2017, 07:47:10 pm
Transient/ESD protection resistor and MOV's  made a really easy DIY robustness improvement.
The MOV's i picked: aliexpress.com/item/1/32791292139.html not sure if its perfect match anyone has an idea?
datasheet 07D681K http://www.mouser.com/ds/2/54/OV07D-777763.pdf (http://www.mouser.com/ds/2/54/OV07D-777763.pdf)

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 25, 2017, 10:25:40 pm
Transient/ESD protection resistor and MOV's  made a really easy DIY robustness improvement.
The MOV's i picked: aliexpress.com/item/1/32791292139.html not sure if its perfect match anyone has an idea?
datasheet 07D681K http://www.mouser.com/ds/2/54/OV07D-777763.pdf (http://www.mouser.com/ds/2/54/OV07D-777763.pdf)

I will ask you the same thing I asked people who were suggesting populating the MOVs, how do you know you improved it?   Do you just feel it is improved or did you run some sort of tests?   
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: kcbrown on May 26, 2017, 01:59:44 am
I will ask you the same thing I asked people who were suggesting populating the MOVs, how do you know you improved it?   Do you just feel it is improved or did you run some sort of tests?

Perhaps a better question is: did it make it worse?

It'd probably be rather dumb to presume that it improved anything, so I wouldn't use it to measure mains voltages or anything of that sort, but if it's down to either living with the meter as it is or putting in those components, which is the better choice?

 :-//
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: P90 on May 26, 2017, 02:03:57 am
Transient/ESD protection resistor and MOV's  made a really easy DIY robustness improvement.
The MOV's i picked: aliexpress.com/item/1/32791292139.html not sure if its perfect match anyone has an idea?
datasheet 07D681K http://www.mouser.com/ds/2/54/OV07D-777763.pdf (http://www.mouser.com/ds/2/54/OV07D-777763.pdf)

I will ask you the same thing I asked people who were suggesting populating the MOVs, how do you know you improved it?   Do you just feel it is improved or did you run some sort of tests?



It gives one the same sence of security as wraring a aluminium foil hat...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on May 26, 2017, 11:30:33 am
I will ask you the same thing I asked people who were suggesting populating the MOVs, how do you know you improved it?   Do you just feel it is improved or did you run some sort of tests?

Perhaps a better question is: did it make it worse?

It'd probably be rather dumb to presume that it improved anything, so I wouldn't use it to measure mains voltages or anything of that sort, but if it's down to either living with the meter as it is or putting in those components, which is the better choice?

 :-//

I would say ANY time someone would modify a handheld meter it would make it worse!  It's just being stupid!  If you are a child or novice, even more so.  Adult's I would expect would know better.  The videos I make showing the shortcomings of the UT61E are for educational purposes only. If the meter were to end up in someone else's hands, it is CLEARLY marked.   

I've stated my views on this many times but seems it's not clear to you.  If it's down to either living with the meter as it is or putting in those components, which is the better choice?  Live with it!  Next time buy a tool that meets your needs! 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: kcbrown on May 26, 2017, 09:32:22 pm
I would say ANY time someone would modify a handheld meter it would make it worse!  It's just being stupid!  If you are a child or novice, even more so.  Adult's I would expect would know better.  The videos I make showing the shortcomings of the UT61E are for educational purposes only. If the meter were to end up in someone else's hands, it is CLEARLY marked.   

I've stated my views on this many times but seems it's not clear to you.  If it's down to either living with the meter as it is or putting in those components, which is the better choice?  Live with it!  Next time buy a tool that meets your needs!

Thanks for restating your views here.  I either hadn't seen your messages where you stated them this way, or didn't remember them (you'll find that my memory is basically the worst on the planet -- it's almost completely worthless).  Sorry for the frustration.

I suppose that even if the person who performs the modifications knows what they're doing (e.g., they design multimeters for a living), they still can't know that they've improved it without actually performing the proper tests.  And they most certainly can't know that the revisions will result in the meter passing the safety standard tests without performing those same tests, which tend to be destructive.  And even then, I wouldn't be surprised if proper testing requires that a batch of meters be tested in that manner to make the test statistically valid.

I guess from a safety standpoint, if you don't know that your changes have improved things, you have to presume that they've made things worse.  That seems sensible.

Oh, and as an aside, for what it's worth, I quite appreciate your irreverence in your videos.  It's quite refreshing.    :-+
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: schmitt trigger on May 26, 2017, 09:59:00 pm
If anything, my only concern would be the Rotary selector brushes making intermittent contact with the board tracks.

I know, I know. This technique is used in most, if not all meters with rotary selectors.
All I'm saying......The quality of those bronze "brushes" determine the instrument's usable life.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Spaghetti_142 on May 28, 2017, 04:54:59 am
No knocking, but I absolutely love my UNI-T. For the price it blows away Fluke. I use it at my electrical lab and I love it. Couldn't get the software to work with the meter, a little outdated, other than that, I'm good Good luck to you!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ProBang2 on May 28, 2017, 03:27:52 pm
 
[...] Couldn't get the software to work with the meter [...]

Where is the problem? Do you connect with a RS232 or an USB cable? At least regarding the USB connection I can assure you: The (probably) latest SW version 4.01 works fine with Windows7 (64-bit) and even with Windows10 (64-bit).

In case you have only an older SW version: You can download this version here (http://www.batronix.com/downloads/UNI-T/UT61/UT61E_V4.01.exe).
(IIRC Install the SW first, then connect the UT61E.)

If you don´t want to use the original Uni-T software: There are at least two alternatives (as freeware) available.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on June 27, 2017, 04:12:05 pm
Here is another headsup, UT61E can now be logged on the Raspberry Pi 3 (Raspbian OS) through a professional-like / commercial-like high maturity software called DEX.

Of course, one must connect the UT61E through its original serial data cable (RS232, female plug) to the raspi "somehow". There are 2 straight-forward commercial solutions: either using a FDTI-chipset based USB2Serial adapter or using a RS232 shield (Pi Hat). At this point i cannot recommend using USB2Serial adapters based on the CH340/341-chipset (or variants like the HL340) because they are not straightforwardly supported by the latest Raspbian builds. One can get CH340-based items to work on raspi but it is a frustrating hassle afaik. In contrast, FDTI is supported directly by Raspbian, so you're good to go, no need to install Linux ARM drivers from a CD or floppy disk  :-DD

Apparently the cost for a nice quality (http://www.ebay.de/itm/391329359200) FDTI usb2serial adapter is similar to the price of a Pi Hat RS232 shield, around 10EUR shipped. Of course a usb2serial adapter is more flexible, you could use it on any computer, PC, Mac, Linux computer. Your choice.

So for people who need to do tens of hours of logging, for example overnight, they can use the headless raspi from now on. DEX saves the logged/graphed data in various formats including *.CSV. UT61E support is new in the latest version of DEX, here a screenshot of the device selection dialog:

(https://abload.de/img/ut61eraspic7owz.png)

While DEX support of UT61E is brand new (since v3.3.0), DEX support of the raspi operating system is new in itself (since v3.2.9 (http://savannah.nongnu.org/news/?group_id=10545))! Kudos to the maker of the great software  :clap:
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: RedSky on June 28, 2017, 11:58:51 am
Anyone had trouble with UNI-T 61E and getting accurate measurements on DC-DC converters?

Mine simply has no hope of accurately measuring the DC input to a synchronous DC converter running @ 64kHz, which runs in the 12-100V region input to adjustable output DC.
It's off by several volts DC no matter what the input or output, as much as 10 volts or more in worst case scenario.   Even some cheap $10 meters I have do a much better job, as well as a much more budget UNI-T 33A.
The input is from a solar panel so it's fairly stable DC supply and no it's not fluctuating sun causing it.   My UNI-T 70D shows accurate voltage readings, and the DC Converters own meter also shows accurate voltage, which is a micro using internal ADC's measuring off a resistor divider (averaged readings)

The input to the DC converter has little AC voltage present <100mV on the signal, and a number of low ESR capacitors ceramic and bulk low ESR electrolytics on the input.

My UNI-T61E is super accurate when tested with a DC voltage reference and on ohms range when tested with 0.1% ohm resistors.

Anyone else seen issues like this?

Apologies if this has already been mentioned, I read most of this (huge) thread.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on August 30, 2017, 01:22:24 pm
This thread never gets old i guess...  :popcorn:

I couldn't find a RL photo of the European version of the multimeter, so here we are:

(https://abload.de/img/ut61eeuropeannqkb7.jpg)

As you can see, the ratings are very different from the International version (feel free to compare with your own unit)! Also inside, the PCB and electronics are very different: more components and higher quality more expensive components, fuses, etc. Some trace sections of the PCB are similar but about 40% is different, easily seen from the traces and populated components. Yeah sure, mostly for better input protection and for really matching the ratings printed on the front. Those lowered ratings were then certified by the top highest German Authorities both GS (https://de.wikipedia.org/wiki/Gepr%C3%BCfte_Sicherheit) and TÜV (https://de.wikipedia.org/wiki/T%C3%9CV), which are commonplace language items in geman households.

So for the International version UNI-T designers simplified the schematics, reduced the number of components, populated cheaper components to cut the costs and the retail price, and at the same time they raised the labeled ratings oic 
:-DD

My neighbor got his European version from a Dutch retailer but the instruction manual was in geman, here are the source PDFs for your reference:

Needless to say, typical pricing for the European version is expensive at 85EUR (2017), whereas the International version can be bought at 45EUR (ebay). The current packaging list is also slightly different: the UT61E nowadays comes with a 'bracketed' holder for the transistor measurement (you can see part of the bracket in the above photo) and with a USB data cable instead of the serial data cable. I didn't have good experience with the USB data cable before, though, as described possibly on another forum. Hence I continue employing the serial data cable and, if needed (see my previous post), a Serial-to-USB adapter based on the FTDI chipset series.

If people have/use the UNI-T USB data cable and are wondering, just do a 24.0h logging test (of voltage or current) and check if your Excel file is complete:
24h * 3600s/h * 2Hz = 172800 data points
Your Excel file should have 172800+ rows. Does it? Well, mine didn't when i used the UNI-T USB data cable. It did when i used the UNI-T serial data cable. There you have it. I don't trust the UNI-T USB data cable anymore.

Cheers, going on summer vacation now, bye!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fungus on August 30, 2017, 01:32:31 pm
Where can people buy them?

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on August 30, 2017, 01:46:38 pm
People can buy the European versions of UNI-T products from the German importer Reichelt, look out for the "TÜV GS"-logo printed right below the LCD screen:
https://www.reichelt.de/UNI-TREND/Herstellersuche/103/index.html?ACTION=103&LA=103&MANUFACTURER=UNI-TREND (https://www.reichelt.de/UNI-TREND/Herstellersuche/103/index.html?ACTION=103&LA=103&MANUFACTURER=UNI-TREND)

The EU version is also sold by committed chinese :palm: vendors on Alibaba and Aliexpress but that's none of my business  :o
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fungus on August 30, 2017, 01:53:56 pm
OK.  :-+

PS: I didn't know Uni-T made cheapo desktop meters (https://www.reichelt.de/Tischmultimeter-digital/UNI-TREND/2/index.html?ACTION=2&LA=103&MANUFACTURER=UNI-TREND&GROUPID=5893&SID=95WabB86wQAT0AAHIESr48b1d253644ac56ba33a1a35474fd0e08). They're cute - a bit like those old Fluke 8050As!  :D

(https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/?action=dlattach;attach=346238;image)

(but autoranging)

Edit: And weirdly enough, much cheaper there than on eBay.  :-//

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: hans_ober on September 03, 2017, 04:34:16 am

The EU version is also sold by committed chinese :palm: vendors on Alibaba and Aliexpress but that's none of my business  :o

Is it? I've tried searching aliexpress for "ut61e gs" and "ut61e eu" but never found anything.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: analogix on September 03, 2017, 06:27:09 am
I also didn't find the European "GS" version on any of those Chinese sites (or perhaps I did but didn't trust if that was really true. Actually I believe I did find a "GS" version pictured somewhere, but asked and it turned out to be the wrong photo, meaning they sold the Chinese version anyway), assuming it's not possible for Chinese dealers to get it through the usual channels.
I ended up buying mine from Reichelt (https://www.reichelt.de/Digital-Multimeters/UT-61E/3/index.html?ACTION=3&LA=446&ARTICLE=97151&GROUPID=4058&artnr=UT+61E&SEARCH=UT%2B61E) in Germany. Haven't opened it up yet though.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Fungus on September 03, 2017, 07:56:20 am
I didn't know Uni-T made desktop meters. They're cute

Update:

a) I saw a picture of one in context, they're not cute at all, they're massive.     :wtf:

b) I also saw a pic (https://www.eevblog.com/forum/testgear/uni-t-utd2102cel-vs-rigol-ds1102e/msg17865/#msg17865) of what's inside. The oversized case is mostly filled with marketing:

(https://www.eevblog.com/forum/index.php?action=dlattach;topic=1331.0;attach=3523;image)

Should we :-DD or should we  :palm: ?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: dinoboy on September 03, 2017, 12:44:18 pm
assuming it's not possible for Chinese dealers to get it through the usual channels.
Sorry i confused Aliexpress with Alibaba :palm: .

Believe me, UNI-T factory sales reps are more than willing to sell their products at MOQ to any (serious) Chinese or non-Chinese company at MOQ, such as wholesalers or trading companies or importers. Vely small Aliexpress businesses or private individuals wouldn't be able to buy from UNI-T factory direct. I've got a quote from a "Manufacturer, Trading Company (Total Employees: 51 - 100 People)" on Alibaba who quotes the following prices no matter who you are (b2b client, international importer, local retailer, end consumer, or small business):
Quote
1000pcs UT61E Normal version - 35.0US$ Fob China port
1000pcs UT61E German version (TÜV/GS) - 57.0US$ Fob China port

So these are pretty much the lowest prices, if you (individual or business) go through a Chinese middleman. However I don't believe that Reichelt goes through any trading company but purchases their UNI-T stuff at MOQ off the UNI-T factory direct. At the same time I have reason to believe that the quote includes a rather low margin for that Alibaba Chinese trading company; exfac prices could be 20% lower, please don't quote me on that:
1000pcs UT61E Normal version - 28.0US$ exfac *my guess*
1000pcs UT61E German version (TÜV/GS) - 45.6US$ exfac *my guess*

The jump from 45.6$ to 85€ (Reichelt) is steep .. and my neighbor accepted it  :palm:
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: 001 on October 30, 2017, 07:08:36 pm
Huh-huh  :-DD

UT61E invented about 10 years ago

What new about nowday substitutions?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Nawual on November 08, 2017, 02:25:41 pm
After i have read 41 pages...ummm...where can i buy the versión gs with a good price?.Thanks
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rango on November 15, 2017, 04:02:58 am
Slap the 3 low capacitance MOV units in, and be done with it. The limiting factor will be the PTC in any case, 1kV and it will fry itself apart in a second or so. Choose the voltage to suit your normal use, and as they mostly come from RS in packs of 10 you will have some spares. If you do blow them up the meter will not survive in any case.

In my case I just used 2 275V MOV units ( 7mm) in series, as I did have the remains of a 10 pack around, so using the 6 was easier than either placing an order and wait till I had the minimum order price in other parts, or paying the $20 courier charge RS puts on here for small orders. Still have 1 left, after replacing 3 MOV units on other equipment.

@SeanB so reading threw last 20 pages i gathered that slapping those 3 movs it would increased chances of input protection. Why 3 not 4 or 2? Which spots GS1 threw GS4 ? If only 2 then which spots? Wouldn't this 30pF Vishay Vishay VDRS - E Series Metal Oxide Varistor 30pF 5A, Clamping 1200V, Varistor 750V (178-059) be best option as it has lowest capacitance rating hence not throwing up capacitance rating too much out of calibration on 61e when measuring capacitance as compared to other once listed below? Would this affect any other measurement readings and to what degree will it effect capacitance rating? Also those come in pack of 5 so would also be ideal unlike pack of 10?

Does anyone know what those original green Mov's part numbers are on GS version PCB or would those movs listed below be better since their rating is higher for voltage? What about fuses replacement/upgrade/Siba? Would that effect mA readings for example?

It seems latest PCB versions of 61e are same as GS so it looks like installing those Movs would make this GS DMM minus 10A trimmer? Why is that trimmer missing and what effect having the trimmer in CHI version have with those movs do?

"it seems that the PCB is the same between the world-wide and German versions today, but I've not been able to verify that - the photos I've seen of the German PCB seem to be missing the 10A trimmer (by the 10A fuse, between the input sockets), amongst other differences.

There are a lot of beefy SMT diodes, which I presume are also for protection. We have a single IR LED for the PC interface, with a 4069 CMOS hex inverter next to it. Under the screen is the divider resistor network - I've not removed the screen to investigate further, but it appears to be encapsulated in plastic, so I can't tell if it's a nice thick-film network like Fluke use (as if it would be!). As with the UT210E, the crystal is 3.999MHz rather than the usual 4MHz."

https://www.markhennessy.co.uk/budget_multimeters/unit_ut61e.htm (https://www.markhennessy.co.uk/budget_multimeters/unit_ut61e.htm)

If anyone else would like to jump in and help me out that would be greatly appreciated.

Any other Parts besides green movs that appear on GS PCB board that could be modded into CHI PCB board to reflect original GS design?

Here are the mov parts i gathered that can be used in GS1-GS4 spots

http://uk.rs-online.com/web/p/metal-oxide-varistors/0178059/?searchTerm=178059&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D626572266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B362C377D7C5C647B31307D7C28283F69292852537C5253207C52532D293F5C647B337D285C73293F5B5C732D2F255C2E2C5D285C73293F5C647B332C347D292426706F3D3126736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D313738303539267374613D3031373830353926 (http://uk.rs-online.com/web/p/metal-oxide-varistors/0178059/?searchTerm=178059&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D626572266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B362C377D7C5C647B31307D7C28283F69292852537C5253207C52532D293F5C647B337D285C73293F5B5C732D2F255C2E2C5D285C73293F5C647B332C347D292426706F3D3126736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D313738303539267374613D3031373830353926)

https://www.mouser.com/ProductDetail/Bourns/MOV-07D681K/?qs=lgttKnAd%252b2CCDLVYA77ICw%3D%3D (https://www.mouser.com/ProductDetail/Bourns/MOV-07D681K/?qs=lgttKnAd%252b2CCDLVYA77ICw%3D%3D)

http://uk.rs-online.com/web/p/metal-oxide-varistors/7606964/?searchTerm=7606964&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D626572266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B362C377D7C5C647B31307D7C28283F69292852537C5253207C52532D293F5C647B337D285C73293F5B5C732D2F255C2E2C5D285C73293F5C647B332C347D292426706F3D3126736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D37363036393634267374613D3736303639363426 (http://uk.rs-online.com/web/p/metal-oxide-varistors/7606964/?searchTerm=7606964&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D626572266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B362C377D7C5C647B31307D7C28283F69292852537C5253207C52532D293F5C647B337D285C73293F5B5C732D2F255C2E2C5D285C73293F5C647B332C347D292426706F3D3126736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D37363036393634267374613D3736303639363426)

http://uk.rs-online.com/web/p/metal-oxide-varistors/7118149/?searchTerm=7118149&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D626572266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B362C377D7C5C647B31307D7C28283F69292852537C5253207C52532D293F5C647B337D285C73293F5B5C732D2F255C2E2C5D285C73293F5C647B332C347D292426706F3D3126736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D37313138313439267374613D3731313831343926 (http://uk.rs-online.com/web/p/metal-oxide-varistors/7118149/?searchTerm=7118149&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D626572266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B362C377D7C5C647B31307D7C28283F69292852537C5253207C52532D293F5C647B337D285C73293F5B5C732D2F255C2E2C5D285C73293F5C647B332C347D292426706F3D3126736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D37313138313439267374613D3731313831343926)

http://uk.rs-online.com/web/p/metal-oxide-varistors/2897109/?searchTerm=2897109&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D626572266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B362C377D7C5C647B31307D7C28283F69292852537C5253207C52532D293F5C647B337D285C73293F5B5C732D2F255C2E2C5D285C73293F5C647B332C347D292426706F3D3126736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D32383937313039267374613D3238393731303926 (http://uk.rs-online.com/web/p/metal-oxide-varistors/2897109/?searchTerm=2897109&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D626572266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B362C377D7C5C647B31307D7C28283F69292852537C5253207C52532D293F5C647B337D285C73293F5B5C732D2F255C2E2C5D285C73293F5C647B332C347D292426706F3D3126736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D32383937313039267374613D3238393731303926)

This one does not state capacity rating anywhere
https://www.tme.eu/gb/details/siov-s20k625/tht-varistors/epcos/b72220s0621k101/ (https://www.tme.eu/gb/details/siov-s20k625/tht-varistors/epcos/b72220s0621k101/)

Here is an idea how about we open up fund me page for joe smith and each of us fund few $ to buy 61e and just add movs and put it threw his test without any other board modifications (cutting pcb lines and other stuff he did)? That way we know if it survives input protection of not and no one has to sacrifice it's meter and cost to each of us would be $2-4. 

Pic attached Not mine UT61e GS PCB board
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Rango on November 15, 2017, 01:44:28 pm
I picked up a brand new UT61E.   It appears identical to the one 5KY had sent.   Metal can and all.   

So, what I would like to do if modify this meter with the MOVs people are recommending, or use the parts that are available in the one being supplied to Germany.   I will then retest it to failure and see if there are any improvements. 

Keep in mind the 61E and D never made it to the mini surge test.  They both failed ESD with that little grill starter.

@joesmith did you ever mod chi 61e with only movs seen in GS version (which btw is also same movs as in your 181A i think) to see if it survived ESD test and maybe up 1000V test? Basically that would be my goal with movs and fuses upgrade. I'm not sure why 1000v fuses are so damn expensive. It's just a wire inside isn't?

I see Holdpeak 35$ meter pretty much survived almost all of your test. Makes you go hmmm.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: racemaniac on December 27, 2017, 03:26:23 pm
I recently also received a UT61E from china, seems like a fun device.
bought it since i wanted something basic that could log data.

One issue i had with mine when it arrived was a few segments of the LCD not lighting up properly (you could only see them light up when looking at an angle) (which luckily meant the signal was there, and the segments weren't broken :) ).
Googled a bit and found videos of people cleaning the pads on fluke multimeter pcb's that connect to the lcd. Opened up my ut61e, and i saw the same style of pads, and a few were very clearly dirty, cleaned them up with a q-tip with some acetone on it, and the lcd is now showing perfectly :).
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Nisei on February 26, 2018, 11:59:04 am
GS model and regular model next to eachother.
(https://image.ibb.co/fQs2yH/Uni_t.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: wasyoungonce on March 20, 2018, 03:05:48 am
Urggh

My UT61E is again out of calibration, see here: 
https://www.eevblog.com/forum/testgear/how-good-is-the-ut61-series/msg1214739/#msg1214739 (https://www.eevblog.com/forum/testgear/how-good-is-the-ut61-series/msg1214739/#msg1214739)

Was measuring 12V it read around 10.2V. Its done this before.  I don't have the PCB ver and spare pads to install an LT1970 Vref...although I could do it.  But that's not the issue...it keeps going out of cal by quite a bit.  Any suggestions?  Maybe I should first change the POT I mean there is not much to go wrong here looking at the schematic.

An unreliable multimeter is useless..so I have to fix it.  Using one of my many backuo meters atm

Brendan
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: evgen.05 on March 20, 2018, 03:31:19 am
Urggh

My UT61E is again out of calibration, see here: 
https://www.eevblog.com/forum/testgear/how-good-is-the-ut61-series/msg1214739/#msg1214739 (https://www.eevblog.com/forum/testgear/how-good-is-the-ut61-series/msg1214739/#msg1214739)

Was measuring 12V it read around 10.2V. Its done this before.  I don't have the PCB ver and spare pads to install an LT1970 Vref...although I could do it.  But that's not the issue...it keeps going out of cal by quite a bit.  Any suggestions?  Maybe I should first change the POT I mean there is not much to go wrong here looking at the schematic.

An unreliable multimeter is useless..so I have to fix it.  Using one of my many backuo meters atm

Brendan
Blue trimmer VR1 - is bullshit. I have the same problem. Replace and calibrate it - and calibration will never goes out.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: wasyoungonce on March 20, 2018, 03:54:25 am

Blue trimmer VR1 - is bullshit. I have the same problem. Replace and calibrate it - and calibration will never goes out.

Many thanks I'll do that and post back.

Brendan

edit:
Pot ordered.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Stinger on March 25, 2018, 07:44:46 pm
Hello,

No 2018 version of UT61E with backlight ?  ???
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on March 25, 2018, 08:00:08 pm
Hello,

No 2018 version of UT61E with backlight ?  ???
Really?   Is it stall marked 61E?   It seems there were some problems with the data sheets.  Are you sure this was not a misprint?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on March 25, 2018, 08:02:14 pm
I picked up a brand new UT61E.   It appears identical to the one 5KY had sent.   Metal can and all.   

So, what I would like to do if modify this meter with the MOVs people are recommending, or use the parts that are available in the one being supplied to Germany.   I will then retest it to failure and see if there are any improvements. 

Keep in mind the 61E and D never made it to the mini surge test.  They both failed ESD with that little grill starter.

@joesmith did you ever mod chi 61e with only movs seen in GS version (which btw is also same movs as in your 181A i think) to see if it survived ESD test and maybe up 1000V test? Basically that would be my goal with movs and fuses upgrade. I'm not sure why 1000v fuses are so damn expensive. It's just a wire inside isn't?

I see Holdpeak 35$ meter pretty much survived almost all of your test. Makes you go hmmm.
Late to the party on this one...  I went over what I believe to be the cause of the problem in this video.   I did not need to try the MOVs on a good meter to prove it it would fail or not. 

https://youtu.be/cMutvk_6xhY?list=PLZSS2ajxhiQDrk4o1Y45auwK7LomjnNBU&t=1436
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on March 25, 2018, 08:23:21 pm
Hello,

No 2018 version of UT61E with backlight ?  ???
Really?   Is it stall marked 61E?   It seems there were some problems with the data sheets.  Are you sure this was not a misprint?
Looks like they just never corrected their website.  Read page 41 of the manual. 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: wasyoungonce on March 26, 2018, 06:37:29 am
Ok re: my UT61E was loosing cal and was all over the place DC volts.  Put in new 2K pot adjusted roughly with variable PSU...its all appears ok time will tell.  Waiting for cheap fleabay voltage reference to arrive to cal it better.

https://www.ebay.com.au/itm/262940287208 (https://www.ebay.com.au/itm/262940287208)

Yes I know they are not that great but its good enough for me. :-+

I'll post back when I get it an re-cal. Thanks to all.
Brendan
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: wasyoungonce on April 06, 2018, 02:59:19 am
Ok meter Cal was all over the place...replace 2K POT dud rough Cal to variable PSU now have Cheap Chinese voltage std AD584KH, on ref IC, says AD584-M on plastic case.
Here (https://www.ebay.com.au/itm/AD584KH-Precision-Voltage-Reference-Module-4-Channel-Single-button-Operation/262940287208?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649).  Has inbuilt battery and odd USB recharge connector.  Sigh I hate that but I couldn't build it for that price ~ $20 Aud.

Didn't come with any Cal info. 

Anyway my UT61E wasn'yt out much and is behaving much better since the Pot change, no wild changes in calibration.  I did tweak the Cal a little, its all good.  Now I want a Resistance std...probably just get some precision resistors.  I think I'm just been bitten by the bug!  Oh my older multimeters are shall we say..."in need of calibration" :-DD

Many thanks to the forum members for help. :-+
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: escape on April 16, 2018, 12:54:10 am
Chinese vs EU version differences aside, are there any counterfeit/knockoff UT61Es out there?  If so, how can you tell it's a knockoff?

I'm seeing a bunch of them on US ebay for under $35 (including free shipping from within US), and wondering why the price is so low.  I'm guessing they don't carry official Uni-T warranty.

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: escape on April 18, 2018, 01:12:16 pm
Didn't come with any Cal info. 
Without actual calibration info against a known reference meter, that AD584 box is fairly useless.  It should have come with actual reference values printed on a sticker attached to the bottom of that AD584 rig.  Mine looks like this:

(https://i.imgur.com/FDBpQfp.jpg)

Of course there is some controversy as to whether these sticker values are actual measured values or just some random numbers that someone made up or copied from another sticker.   |O
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: Stinger on April 18, 2018, 10:51:11 pm
We believe a F version with factory backlight and ESR mesurement.  ;D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on April 19, 2018, 02:57:56 am
Didn't come with any Cal info. 
Without actual calibration info against a known reference meter, that AD584 box is fairly useless.  It should have come with actual reference values printed on a sticker attached to the bottom of that AD584 rig.  Mine looks like this:

(https://i.imgur.com/FDBpQfp.jpg)

Of course there is some controversy as to whether these sticker values are actual measured values or just some random numbers that someone made up or copied from another sticker.   |O

Even with the sticker, and even if they did correctly copy it from some random HP34401A, you have no idea if the meter they checked it against was even in current cal.   You could have the standard sent in and get a NIST traceable report for it but it may cost far more than the little device cost.   
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: DiddlyJackSquat on April 19, 2018, 04:09:30 pm
One of my mates blew up his UT61E that i sold him  :palm:

idk how he blew it exactly as details are scarce but he told me he blew it in current mode measuring a lipo in current, with the 10A ports and I told big fat bad idea... Now all readings are off.

I'm getting it later from him so i might be able assess the damage

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: escape on April 26, 2018, 12:56:29 pm
Speaking of blow ups, I had a major brain fart yesterday... I had my UT61E in "A" position, test leads connected to COM and 10A sockets.  One test lead was connected to negative terminal of a fully charged 12V car battery, and then I attempted to touch the positive battery terminal with the other test lead.  I only touched the positive terminal for a split second since I saw a spark at the positive terminal and heard the DMM beep.

The DMM still measures voltage, but not current on the 10A socket.  Hopefully I only blew the fuse and nothing else.  Is BS1362 the correct replacement fuse?  I have the Chinese version, not the German version.

Thanks!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: DiddlyJackSquat on April 26, 2018, 04:44:26 pm
Speaking of blow ups, I had a major brain fart yesterday... I had my UT61E in "A" position, test leads connected to COM and 10A sockets.  One test lead was connected to negative terminal of a fully charged 12V car battery, and then I attempted to touch the positive battery terminal with the other test lead.  I only touched the positive terminal for a split second since I saw a spark at the positive terminal and heard the DMM beep.

The DMM still measures voltage, but not current on the 10A socket.  Hopefully I only blew the fuse and nothing else.  Is BS1362 the correct replacement fuse?  I have the Chinese version, not the German version.

Thanks!

Yes, BS1362 is the correct replacement fuse.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: wasyoungonce on June 01, 2018, 12:25:07 pm
To member "Sonny"....you PM'd me but I cannt reply as your post box is full....

So I'll post here and hope you notice as it was wrt to this thread.....

Sorry for the late response...I've been in hospital for last 6 weeks...yet another spinal fusion (I've had quite a few lumber and cervical).   This one worked very well but I've been spending some times on drugs and on the net...a dangerous combination..... :wtf:

Anyway as for the PCB ver...I think I posted pics but am looking for them...or I'll tear it apart when I can.

Pot I used was 2K , 785-9828 RS mrn.  785-9828 (https://au.rs-online.com/web/p/trimmer-resistors/7859828/?relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D626572266C753D656E266D6D3D6D61746368616C6C26706D3D5E285C647B362C377D5B4161426250705D297C285C647B337D5B5C732D2F255C2E2C5D5C647B332C347D5B4161426250705D3F292426706F3D3126736E3D592673723D2673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D3738352D39383238267374613D3738353938323826)

Its a 3296Z Bourns pot, 2K 10% +/-100PPM/C, so yeah could have done better here!   I think it was what I could get at the time!.  Another Problem is its centre legs is offset so I had a bit of bending to do prior to fitting... :palm:

I'll do pics soon ummm it didn't have pads to vref IC!

Oh yeah its kept cal ever since changing the pot!

Brendan

edit:
Jeez Sonny your postbox is still full....I cannot PM back to you till ya empty !
And correct pot should have been Bourns 3296x pot as these pins are inline pins and its side adjust or 3296W for a top adj pot.  I'm sure top adj will fit ok. The RS 3296X pot is RS number: 521-9912, mfgr mrn: 3296X-1-202LF, RS cost $4.30 ea.

 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sonny on June 18, 2018, 07:38:40 pm
Jeez Sonny your postbox is still full....I cannot PM back to you till ya empty !
Hello,
Thanks for your post. My postbox is 340% full, I suppose Dave did another shrink to the accounts some time ago. I removed 15 messages and my inbox is still full. Do you know where are the requirements for the accounts, because I can't find them.

I hope you are doing well now after your spinal fusion?

I also noticed that it's not Bourns 3296Z, because of the pins alignment. Bourns 3296X seems to be the best choice. I measured the pot in my UT61E and it shows around 500 ohms. I think 3296X with 1k will be the perfect fit and it will provide better resolution for the calibration.
Regards,
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: wasyoungonce on June 19, 2018, 11:03:59 am
There are different versions with different pots ( dividor reference networks)so ensure you replace the OEM with the same specified value.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sonny on June 19, 2018, 11:19:29 am
There are different versions with different pots ( dividor reference networks)so ensure you replace the OEM with the same specified value.
Hello,
Thanks for your message. As far as I know VR1 is the same 3296X pot with 2k value for all UT61E in production (just different brands). Interesting enough in the manual says 1k for VR1.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on June 20, 2018, 10:56:32 am
In Nov 2016, I had measured the temperature drift of my new UT61E and made a video were I compensated it.  I had also changed out the one trimmer pot.  Someone had asked about long term drift and I mentioned I would start collecting some data from mine.  It sounds like some people are seeing a lot of drift.  I can't help but wonder if this is operator or the meter.   

Anyway, here is some data from my UT61E after the temperature compensation taken on 11-21-16:
1mV: 1.02
1V: 1.0001
10V: 10.002
1nF: 1.003

I have had the meter apart a few times since then to make other modifications to it including the larger shunt for measuring 20A and attempting to improve the burden voltage in the uA range.  However, I have been careful not to adjust the trimmers that would effect this little study. 

You can see the in the mV range the meter appears to have a change of 30uV.  However, it's way to small of a change to hang my hat on and way too little time has passed.   I would expect the meter would be fairly stable.  Maybe people are using an unstable source to look at drift?

It's been another 6 months since I last measured the drift of my UT61E.   


Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ziplock9000 on June 21, 2018, 03:21:23 am
Speaking of blow ups, I had a major brain fart yesterday... I had my UT61E in "A" position, test leads connected to COM and 10A sockets.  One test lead was connected to negative terminal of a fully charged 12V car battery, and then I attempted to touch the positive battery terminal with the other test lead.  I only touched the positive terminal for a split second since I saw a spark at the positive terminal and heard the DMM beep.

The DMM still measures voltage, but not current on the 10A socket.  Hopefully I only blew the fuse and nothing else.  Is BS1362 the correct replacement fuse?  I have the Chinese version, not the German version.

Thanks!
You say German version.. Isn't it a European version because the reason it's different is due to European safety laws?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ProBang2 on June 22, 2018, 05:28:28 am
You say German version.. Isn't it a European version because the reason it's different is due to European safety laws?

Perhaps that is the case because:
Actually it should be even the "European Version". In Germany this version was necessary because of product liability.
Regarding the european laws - let me make some examples, please:

I hope, I could made it clear. I know: Too much waffling...   :blah: :blah: :blah:
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ziplock9000 on June 22, 2018, 08:37:06 am
That makes sense, thanks  ;D
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: sonny on July 03, 2018, 08:14:07 pm
It's been another 6 months since I last measured the drift of my UT61E.   
You had temperature compensation inside the unit, right?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: rollatorwieltje on July 26, 2018, 01:15:31 pm
Just thought I'd share this, don't leave your UT61E in the sun, the screen will turn black. After cooling it down it recovered. My Fluke 101 and a cheapo Ohmeron mt488e didn't have this "problem".
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: ziplock9000 on July 26, 2018, 02:37:28 pm
That's not specific to the UT61E, it happens to almost all LCD displays
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on July 26, 2018, 10:57:21 pm
It's been another 6 months since I last measured the drift of my UT61E.   
You had temperature compensation inside the unit, right?
Sorry, I missed your question.   The meter has had several modifications done to it at this point.  Yes, I did modify the reference to attempt to make it more stable with temperature.  Originally it was one of the least stable meters I looked it.   It's actually more stable now than many of the meters I have.  I also changed out the 10T trimmer pot while I was at it, assuming this was the major contributor.  It did not turn out to be the problem and I just left the new part in there. 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: jackobo on August 01, 2018, 10:11:16 am
joeqsmith: could you please  specify, what exactly nominal of the resistor you put in between C41-42 in your Part 1 of the robustness video to prevent EMC shock to the main chip?thanks
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: uncle_sem on August 24, 2018, 01:26:59 pm
spare LCDs for ut61e here: https://aliexpress.com/item/UNI-T-UT61E-dedicated-LCD-screen-LCD-size-65mm-43-mm/32906907573.html
got one (well, i'm ordered 3pcs) and very happy about it. I guess it's even little better than original one
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: TheGrave on February 21, 2019, 04:07:01 am
Wondering if these can be clipped on the test leads of UT61E, any clue?

https://www.banggood.com/DANIU-2Pcs-2000V-30A-Crocodile-Alligator-Folders-Safety-Test-Clips-For-4mm-Shrouded-Banana-Plug-p-1157631.html?rmmds=search&cur_warehouse=CN (https://www.banggood.com/DANIU-2Pcs-2000V-30A-Crocodile-Alligator-Folders-Safety-Test-Clips-For-4mm-Shrouded-Banana-Plug-p-1157631.html?rmmds=search&cur_warehouse=CN)

Not sure if a solid connection can be made, perhaps they are for a different purpose but I like to misuse products :)  Otherwise plenty of good reviews on Daniu cables by HKJ...
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: HKJ on February 21, 2019, 06:54:12 am
Wondering if these can be clipped on the test leads of UT61E, any clue?

https://www.banggood.com/DANIU-2Pcs-2000V-30A-Crocodile-Alligator-Folders-Safety-Test-Clips-For-4mm-Shrouded-Banana-Plug-p-1157631.html?rmmds=search&cur_warehouse=CN (https://www.banggood.com/DANIU-2Pcs-2000V-30A-Crocodile-Alligator-Folders-Safety-Test-Clips-For-4mm-Shrouded-Banana-Plug-p-1157631.html?rmmds=search&cur_warehouse=CN)

Not sure if a solid connection can be made, perhaps they are for a different purpose but I like to misuse products :)  Otherwise plenty of good reviews on Daniu cables by HKJ...

They cannot, they are for 4mm unshrouded banana plugs..
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: honeybadger on March 27, 2019, 01:21:19 pm
Hi, my new UT61e just arrived and I must say I am confused about voltage ranges.

at "mV" DC range it says "OL" when nothing is connected.
at "mV" DC range it measure "0.20mV" even with terminals shorted with thick wire with gold plated banana plugs.
at "V" DC range it masure "0.0020V" with shorted terminals.


This shouldn't be happening I guess. With all my others DMMs when voltage is selected and nothing is connected it shows something but definitely not "OL" and when I short the terminals it shows something really close to zero - definitely not 20 digits above zero.

Is this enough for a warranty claim?

edit: accuracy is suppose to be:
220mV +/- (0.1%+5)
2.2V / 22V / 220V +/- (0.1%+2)

So for 220mV range it is suppose to show 0.05mV in worst case scenario -> offset is 400% off.
For 2.2 range it is suppose to show 0.0002 in worst case scenario -> offset is 1000% off.

edit 2:
It measures off by 0.4V at 30V DC. Jesus Christ how is this possible with a new multimeter?  5USD noname is more accurate.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: stj on March 31, 2019, 11:10:04 am
short it with a paperclip, your cable is a recieving antenna - where i live, i power a string of christmas leds dimly with 2m of cable with a cap on the end!!!
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on March 31, 2019, 03:40:18 pm
at "mV" DC range it says "OL" when nothing is connected.
at "mV" DC range it measure "0.20mV" even with terminals shorted with thick wire with gold plated banana plugs.
at "V" DC range it masure "0.0020V" with shorted terminals.


edit: accuracy is suppose to be:
220mV +/- (0.1%+5)
2.2V / 22V / 220V +/- (0.1%+2)

So for 220mV range it is suppose to show 0.05mV in worst case scenario -> offset is 400% off.
For 2.2 range it is suppose to show 0.0002 in worst case scenario -> offset is 1000% off.


It could be my simpleton math skills ...
I assume it's of full scale, so +270uV?    200uV seems in spec.
For 2.2 the volt range, +2.7mV?  2.0mV seems in spec.

Mine has been modified and may not represent how a stock meter would behave.   With no leads attached, selecting the mV function, it will display OL and slowly drop.   Of the meters I have looked at, this meter was one of the worst for temperature drift.  One of the things I had done was compensate mine.  I would have no way of knowing the tolerance of your 30V supply but I have been tracking the drift.  I have attached today's data.  The voltages are checked against a Fluke 731B reference standard.   The 100ohm is a 0.01% 2ppm Caddock part.   Capacitor is a COG.   

Attached picture shows how badly this meter has been treated. 

Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: honeybadger on March 31, 2019, 10:52:52 pm
stj: I will try to make a shorting adapter for future use - two gold bananas and few cm of solid copper wire. But how exactly is the "antenna problem" relevant to DC measurements? I mean none of my other multimeters has this "antenna issue" at DC V ranges.

joeqsmith: correct me if I am wrong - when meter accuracy is described as AA% + BBD this means:
"AA" is linearity error from measured value (not from a full range) described as percentage error from measured value
"BB" is a zero offset error described as count of least significant digits at current range at meters resolution.

So when the leads are shorted the linearity error is suppose to be zero and nothing else and only zero offset plays role here -> thus 200uV offset at 220mV range is ridiculously high.


edit: Brymen BM867s is on the way - thank you for your review of 869. I will try to save this sick UT and give it to someone else.

edit2: something else puzzles me. It shows different value when I switch the polarity of the leads. For example 20.35V at one polarity and -20.10V at reverse polarity - both at 20.0V DC.

edit3: my 30V power supply was checked with UT50E (which I know it measures correctly) and when PSU shows "30.00V" and UT50E (connected in paralell to UT61E) shows "30.02V" I am pretty confident it is really close to 30V.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on March 31, 2019, 11:42:59 pm
joeqsmith: correct me if I am wrong - when meter accuracy is described as AA% + BBD this means:
"AA" is linearity error from measured value (not from a full range) described as percentage error from measured value
"BB" is a zero offset error described as count of least significant digits at current range at meters resolution.

As I stated, I assumed it was percent of full scale.   It could be percent of reading.  It should be in the manual but I don't always see it defined.   If it is of reading, yours is really out of whack.   
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: honeybadger on March 31, 2019, 11:52:37 pm
I guess when it is meant from full range only percentage value is stated - like for an analog meter.

For this DMM it is from reading:
(https://snag.gy/s8goSd.jpg)

I will confront Bangood with this issue.
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on April 01, 2019, 12:06:52 am
Always read the manual first.   :-DD  Looks like you have a bad one. 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: TheNewLab on April 01, 2019, 12:21:12 am
Hi, my new UT61e just arrived and I must say I am confused about voltage ranges.

at "mV" DC range it says "OL" when nothing is connected.
at "mV" DC range it measure "0.20mV" even with terminals shorted with thick wire with gold plated banana plugs.
at "V" DC range it masure "0.0020V" with shorted terminals.


This shouldn't be happening I guess. With all my others DMMs when voltage is selected and nothing is connected it shows something but definitely not "OL" and when I short the terminals it shows something really close to zero - definitely not 20 digits above zero.

edit: accuracy is suppose to be:
220mV +/- (0.1%+5)
2.2V / 22V / 220V +/- (0.1%+2)

So for 220mV range it is suppose to show 0.05mV in worst case scenario -> offset is 400% off.
For 2.2 range it is suppose to show 0.0002 in worst case scenario -> offset is 1000% off.
how is this possible with a new multi-meter ?  5USD noname is more accurate.

The "OL" doesn't make sense to me. I learned from an electrician who says he only gets DMMs that when nothing is connected with or without probes attached the voltage numbers drift all over the place. He calls it ghost voltage and it tells him if an electrical circuit is completely open. Some of my DMMs do that others don't they just show 0.0000 when nothing is connected with or without probes attached.

whoa wait! I had tested a meter in voltage mode probes attached not connected to anything just measuring the air in different places and different rooms. I could swear the voltage changed in the air differently from room-to--room..I, we were drunk as hell though!! :popcorn: _  :-DD
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: TheNewLab on April 01, 2019, 12:39:03 am
Joe, That photo seems within specs, but any drift at all I would think should not happen at all.
I have noticed that when manufacturers include in their calibration sheet both temp and RH% when tested. Never have been sure about that. i mean you buy a multimeter calibrated in Cupertino and you live in Denver. both altitude and humidity is way different.




Mine has been modified and may not represent how a stock meter would behave.   With no leads attached, selecting the mV function, it will display OL and slowly drop.   Of the meters I have looked at, this meter was one of the worst for temperature drift.  One of the things I had done was compensate mine.  I would have no way of knowing the tolerance of your 30V supply but I have been tracking the drift.  I have attached today's data.  The voltages are checked against a Fluke 731B reference standard.   The 100ohm is a 0.01% 2ppm Caddock part.   Capacitor is a COG.   

Attached picture shows how badly this meter has been treated.
[/quote]

I have watched your videos on modding multimeters.  I wondered about is, if changing out MOVs, didn't the calibration change?
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: honeybadger on April 01, 2019, 01:18:32 am
 TheNewLab: the "OL" at mV range might be some residual voltage in the input circuitry capacitance. When it discharge to zero - that is fine with me. My meter shows "OL" indefinitely.

"Ghosts voltages" are also acceptable - there is a high impedance input... it can change by itself. But there is no place for these ghosts when leads are shorted.

The "OL" at mV range gave me an idea. There must be some current leaking into the ADC input - probably after the 10M resistor.
This would clarify:
- "OL" at mV range (current is leaking into ADC and overloading it, it is "grounded" when anything is connected)
- high zero offset
- asymmetry of measurement when switching polarity

Do I understand the schematic correctly (picture attached)?
Am I dreaming or there is no external voltage clamping after the 10M resistor?!


(https://snag.gy/XkU4SO.jpg)
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on April 01, 2019, 10:17:31 am
Joe, That photo seems within specs, but any drift at all I would think should not happen at all.
....
I have watched your videos on modding multimeters.  I wondered about is, if changing out MOVs, didn't the calibration change?

If only zero drift were even possible!   I'm not suggesting you couldn't buy a really low end meter that never changes one place with temp and time...  A meter that can only resolve down to a volt can't display nV of drift.   Check a manual for some higher end equipment and see what they list for temperature requirements.

If you watched those videos, I would imagine there was some data collected before adding the MOVs.   I would assume the MOVs would change the baseline capacitance but I would null that out before making a measurement.   
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: joeqsmith on April 01, 2019, 10:23:01 am
Am I dreaming or there is no external voltage clamping after the 10M resistor?!
If you download the datasheet for the controller, you may gain some insight as to why this is. 

Be aware that the schematic you show may not match your meter. 
Title: Re: UNI-T UT61E Multimeter teardown photos.
Post by: honeybadger on April 01, 2019, 11:21:31 am
joeqsmith: in ES51922 datasheet there is:
Most of pins are protected by the ESD protection circuits. However pins, V+, V-, AGND, DGND and
VR1 are not protected enough because the parasitic effect must be decrease. Therefore enough external
protection is needed for assembling, carrying and keeping. In addition, components connecting to these
unprotected pins have to be soldered on board before the IC is soldered.


I just wonder. There is no PTC... nothing. When the 10M resistor fails (or more probably any of the capacitors around) the current w