Author Topic: UNI-T UT61E Multimeter teardown photos.  (Read 541373 times)

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Offline Mikeva

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #750 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!
 

Offline Lightages

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #751 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.
 

Offline HKJ

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #752 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.
 

Offline Mikeva

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #753 on: October 30, 2014, 07:30:30 am »
Thanks for the reply guys!
Well that make sense....I'll give it a chance.
 

Offline v3n0m3n0

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #754 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 ?

 

Offline Wytnucls

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #755 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.
« Last Edit: December 22, 2014, 02:43:20 pm by Wytnucls »
 

Offline torr032

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #756 on: December 11, 2014, 06:48:09 pm »
I wonder will this improved protection version survive the 2500V test.
 

Offline Lightages

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #757 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.
 

Offline squeck

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #758 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
 

Offline Maxlor

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #759 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?
 

Offline squeck

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #760 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 :)
 

Offline Mad Mart

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #761 on: December 22, 2014, 07:16:49 pm »
Mine also reads 0.060nF without the leads & 0.078 with.
 

Offline Guni

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #762 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. 




 

Offline WackyGerman

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #763 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
 

Offline Guni

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #764 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.
 

Offline Lightages

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #765 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.
 

Offline crystal

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #766 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.

 

Offline centaurian

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #767 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 ?




I'm missing something, or there aren't reserved spots for GDTs on pcb anymore?
 

Offline SeanB

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #768 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.
 

Offline WackyGerman

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #769 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:

 

Offline crystal

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #770 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.
 

Offline Lightages

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #771 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.
 

Offline WackyGerman

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #772 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 .
 

Offline torr032

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #773 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.
 

Offline WackyGerman

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #774 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
 


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