UNI-T UT61E Multimeter teardown photos.

[hgg]

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?

[hgg]

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

Is that true?
Does anybody have any new unit that has the backlight?

[analogix]

I've just received a few days ago a GS approved UT61E which I bought from Reichelt in Germany. 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.

[PedroDaGr8]

I've just received a few days ago a GS approved UT61E which I bought from Reichelt in Germany. 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.

[joeqsmith]

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/

[sdttn]

Hello,
I edited the first message. added pictures again. imageshack f.ed up my acount.
I am proud of this topic. 

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.

[KuroZ]

Just received. Dates to 10 August 2016.

http://yakumo.euamo.moe/temp/ut61e/00.jpg
http://yakumo.euamo.moe/temp/ut61e/01.jpg
http://yakumo.euamo.moe/temp/ut61e/02.jpg
http://yakumo.euamo.moe/temp/ut61e/03.jpg
http://yakumo.euamo.moe/temp/ut61e/04.jpg
http://yakumo.euamo.moe/temp/ut61e/05.jpg
http://yakumo.euamo.moe/temp/ut61e/06.jpg
http://yakumo.euamo.moe/temp/ut61e/07.jpg
http://yakumo.euamo.moe/temp/ut61e/08.jpg
http://yakumo.euamo.moe/temp/ut61e/09.jpg

It seems they didn't piggyback the capacitors.

[dinoboy]

Where can we find a full/complete API description?
Has it been made publicly available as PDF or HTML download?

 

[joeqsmith]

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? 

[dinoboy]

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



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.

[ansic]

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

[joeqsmith]

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

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?   

[kcbrown]

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?

 

[P90]

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

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...

[joeqsmith]

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! 

[kcbrown]

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.   

[schmitt trigger]

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.

[Spaghetti_142]

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!

[ProBang2]

 

[...] 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.
(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.

[dinoboy]

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 

Apparently the cost for a nice quality 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:



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)! Kudos to the maker of the great software 

[RedSky]

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.

[dinoboy]

This thread never gets old i guess... 

I couldn't find a RL photo of the European version of the multimeter, so here we are:



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 and TÜV, 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 


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:

• UT61E Instruction Manual Geman Reichelt
• UT61E Instruction Manual Geman Pollin

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!

[Fungus]

Where can people buy them?

[dinoboy]

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

The EU version is also sold by committed chinese vendors on Alibaba and Aliexpress but that's none of my business 

[Fungus]

OK. 

PS: I didn't know Uni-T made cheapo desktop meters. They're cute - a bit like those old Fluke 8050As! 



(but autoranging)

Edit: And weirdly enough, much cheaper there than on eBay.