A look at the Uni-T UT210E

[joeqsmith]

I've ordered the Amazon demagnetizer - from a direct overseas reseller, it will take 1 month to get to me but it's not that critical.

I've designed and 3d printed this part: https://www.thingiverse.com/thing:4524771 - which I've used on the meter. It took a bit of practice on a magnetized screwdriver to get it to work. I've then adjusted the trimpot on the back. Not sure in which order it should be done, bur now I get about 100mA variation depending on meter orientation while it was only ~20mA a few months ago. I don't think the Earth has changed that much since then. That means, I get -60mA in one orientation and up to +60 or even 100mA on other orientations.

For relative measurements it's perfectly fine, but the annoying thing is that I always have to subtract that offset mentally. As soon as I zero the meter using the button, I lose the 6000 count and it reverts to 2000 counts with the "O.L." display. But it's a minor issue.

I've also slowly nulled out the meter using a magnet but was looking for something more reliable. I might resort to the transformer trick if the newly ordered demagnetizer doesn't do the job.

For other people, please see my post above about decreasing the continuity latency, it really improved on the meter's usabilitu.

I'm missing something as when you zero it, it's a software function.  Obviously if you are changing the setup after nulling, it will be a problem but it sounds like you have some offset that the software can't compensate for.   

Setting the pots are a huge pain.  They are VERY sensitive.  I have yet to have to adjust one outside of the meter I modified.  The only real problems I am seeing is the switches are failing. 

[brainwash]

I've modified the firmware on the meter, one of the improvements is now that it reads up to 6000 on the 2A scale, so up to 6A. This means the milliamp resolution is kept up to 6A. Not sure how linear the response is, but I don't expect it to be unusable.
One of the limitations of the chipset is that, pressing the zero button "resets" the maximum to 2A. So you have to choose between having an absolute error and 6A range or a relative zero and 2A range.
I believe this limitation is baked into the ASIC, as there is no register to control it.

[joeqsmith]

Your previous comment makes sense now.  It's been about 4 years since people were sorting out the tables and that dotless mode had a few problems.  Still, in some cases it's worth it. 

[Trader]

I've modified the firmware on the meter, one of the improvements is now that it reads up to 6000 on the 2A scale, so up to 6A. This means the milliamp resolution is kept up to 6A. Not sure how linear the response is, but I don't expect it to be unusable.
One of the limitations of the chipset is that, pressing the zero button "resets" the maximum to 2A. So you have to choose between having an absolute error and 6A range or a relative zero and 2A range.
I believe this limitation is baked into the ASIC, as there is no register to control it.

Please, could you explain how do you did that? Thank you so much.

[Trader]

$37.85 - UNI-T UT210E
https://www.aliexpress.com/item/1000007078223.html

$3.88 (Color: 2) - CH341A 24 25 Series EEPROM Flash BIOS USB Programmer Module + SOIC8 SOP8 Test Clip For EEPROM 93CXX / 25CXX / 24CXX
https://www.aliexpress.com/item/32902635911.html

Hacking to 10,000 counts

https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/msg1423248/#msg1423248

[Brian of Romsey]

Hi,

  I hope this isn't too far OT.  I'm in Australia (Melb) and I'm looking to buy a UT210E.  The local stores that I'm aware of either don't stock (A & J) or are out of stock until September (RP & Rockby).  Does anyone know of a vendor with stock in the country before I order from the Uni-T Direct Shop Store on AliExpress?  (My last order of one of these was from AliExpress and after AusPost lost it in their Dandenong processing facility I've had to wait over 100 days from order to refund.)

  Thanks, Brian.

[Kean]

Hi,

  I hope this isn't too far OT.  I'm in Australia (Melb) and I'm looking to buy a UT210E.  The local stores that I'm aware of either don't stock (A & J) or are out of stock until September (RP & Rockby).  Does anyone know of a vendor with stock in the country before I order from the Uni-T Direct Shop Store on AliExpress?  (My last order of one of these was from AliExpress and after AusPost lost it in their Dandenong processing facility I've had to wait over 100 days from order to refund.)

  Thanks, Brian.

I can recommend this Sydney based ebay seller https://www.ebay.com.au/usr/autoace
The same people also seem to run this store https://www.ebay.com.au/str/coolcarspareparts
I've bought several Uni-T meters from them as well as some cheap hot air stations.  They will also provide a GST tax invoice on request.

[Brian of Romsey]

Hi Kean,

  Thanks for the tip.  I've placed an order.  I think their price of AU $76.99 is quite reasonable and it includes shipping to Melbourne.  It's due next Monday which isn't too bad in 'these times'.

  Cheers, Brian.

[Thickgit]

Excuse my ignorance I'm but a simple spark. I am trying to understand a problem with the use of RCD's on 230VAC/400VAC supplies. Type AC RCD's do not work when DC current leaks in to the sensing coil, Type A RCD's can cope with <6mA DC current, Type F <10mA DC current and Type B can manage >10mA. This leakage current can come from various sources found in domestic and commercial properties Photovoltaic Systems, EV chargers etc. I bought this clamp meter thinking I could measure this low DC leakage current at the output of the RCD while the load was in place. I am now not sure whether I will get an accurate result when the load is drawing AC current and the leakage is DC current at the same time.

[shved]

Nobody have answered my question about Ali scams. I'll take one for the team.

I've taken a risk and made an order with Aliexpress. Waiting shipping and hoping this isn't a scam.
Will report on how it all went.

Shved

[Fennec]

Nobody have answered my question about Ali scams. I'll take one for the team.

I've taken a risk and made an order with Aliexpress. Waiting shipping and hoping this isn't a scam.
Will report on how it all went.

Shved

Holy this thing cost about 50.-. Are you afraid of starving now or do you have to sell your house? really.

[Johnboy]

<snip>

...is now selling these under the name Voltcraft VC-330.

Possibly worth repeating in view of the "EEVBlog effect".

[Kean]

Excuse my ignorance I'm but a simple spark. I am trying to understand a problem with the use of RCD's on 230VAC/400VAC supplies. Type AC RCD's do not work when DC current leaks in to the sensing coil, Type A RCD's can cope with <6mA DC current, Type F <10mA DC current and Type B can manage >10mA. This leakage current can come from various sources found in domestic and commercial properties Photovoltaic Systems, EV chargers etc. I bought this clamp meter thinking I could measure this low DC leakage current at the output of the RCD while the load was in place. I am now not sure whether I will get an accurate result when the load is drawing AC current and the leakage is DC current at the same time.

I would imagine in DCA mode any AC current should cancel out.

That said, it is worth noting that this meter isn't really suitable for measuring leakage currents as although it has 1mA resolution, the accuracy is +/-(2% + 8 counts) in DCA mode and +/-(3% + 10 counts) in ACA mode.

I have 3 UT210E and current measurement accuracy overall on these is pretty poor in my experience, even at currents of 100's of mA and with careful zeroing.  A no-name clamp meter I bought on ebay years ago is way better.  One day I might try adjusting them.

UT251A with 1uA resolution is suitable for leakage current measurement, but can only do AC current.

[joeqsmith]

That said, it is worth noting that this meter isn't really suitable for measuring leakage currents as although it has 1mA resolution, the accuracy is +/-(2% + 8 counts) in DCA mode and +/-(3% + 10 counts) in ACA mode.

I have 3 UT210E and current measurement accuracy overall on these is pretty poor in my experience, even at currents of 100's of mA and with careful zeroing.  A no-name clamp meter I bought on ebay years ago is way better.  One day I might try adjusting them.

Seems odd you can't get a decent readings at 100's of mA.   I would have pitched them or ran them on the transient generator.   

[Kean]

Seems odd you can't get a decent readings at 100's of mA.   I would have pitched them or ran them on the transient generator.

Yep, I never got around to checking further as I noticed the inconsistency and just stopped trusting them.  I think all of mine read low by something near 10%.
Another thing I will put back on the TODO list - maybe something my new assistant technician can look at when he is out of assembly tasks.

[cdev]

My unt-T is usually within the spec for the range it is on. I demagnetize it now. If you measure high currents you should degauss it periodically. It may have picked up a magnetic charge. When you are finishing with your degaussing, dont just turn the degaussing tool off - slowly remove your Uni-T from the magnetic field.

If you do that you should be fine. I use a bulk tape eraser I have from back in the day.

[joeqsmith]

Seems odd you can't get a decent readings at 100's of mA.   I would have pitched them or ran them on the transient generator.

Yep, I never got around to checking further as I noticed the inconsistency and just stopped trusting them.  I think all of mine read low by something near 10%.
Another thing I will put back on the TODO list - maybe something my new assistant technician can look at when he is out of assembly tasks.

So 2A scale, 200mA low?   That's even worse.   The very first post is more what I would have expected. 

https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/msg560006/#msg560006

I had ran a short term test on drift and even that looked pretty decent. 
https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/msg951626/#msg951626

I wonder if they really cheapened these things up.   Friends of mine all purchased them around the same time.   I have two of these, one is highly modified but the other one, I degaussed and trimmed the adjustments to get the best performance I could.  It has no other mods.  It's a few years old now.   Let me just see how much it's drifted.     

*****

Fresh charge on batteries in the 210E, the DC offset was 440mA.   Degauss brought it down to 17mA which should get us in the ballpark.   Connected the bench supply in series with one of my BM869s meters using the Amps.   210E was zeroed for each reading.

BM869a / UT210E
15.8mA / 17mA
32.7mA / 33mA
168.1mA / 165mA
1.6491A / 1.608A

With the two BM869s in series
BM869s / BM869s / UT201E
2.0069A / 2.0069A / 1.956A
6.057A / 6.057A / 5.80A

Looks like it could stand to be adjusted again.   Still, for a $30 DC clamp with mA resolution, I can't bitch too much.   They have paid for themselves just in hunting down a few automotive leakage problems.   

[brainwash]

I bought mine just to check how much current a motor starter needs (a friend's bike), so basically a single-use meter. The output was as expected and I was happy. Then noticed the charging current was high, while the meter was still clamped. Diagnosed a defective regulator that was feeding >15V into the battery, which is why the batteries were slowly getting killed. Strangely, a voltmeter measured fine -whenever a new battery was installed - but it slowly killed them causing the starter to spin slower and slower.
A few weeks ago had an issue with my car and noticed the battery balancing current was reading weird (it has two lead-acid batteries). This pointed to a big leak which pointed to the navigation unit not shutting down. The advanced car diagnostics did not pick up on this problem, it was just telling me "low voltage" after a few days of sitting, causing me to think that the battery went bust.

So the meter already paid for itself multiple times.

[Stinger]

Hello,

No new hack (or newers models) with min/max, rel, temp and frequencies ?

[Martin72]

I´m afraid not.
But there are the UT211 Models in the same size, they came with 6000counts and better accuracy along.
I would grab one, but unfortunately the interesting 600mA range does only in AC mode exist.

[Brian of Romsey]

Hi,

  My UT210E has arrived today, pretty reasonable time really.

  Does anyone know what the cutoff frequency of the LPF is when VFC is engaged?  The documentation only says: "Entering this mode can accurately measure voltage and current which has VFC frequency conversion. Voltage or current response display is true valid value."  I'm mostly a DC guy so this isn't a big issue, but still nice to know.  The VFC function also seems to affect the stated accuracy of both ACV and ACA.  Note that the stated frequency response is 45 ~ 400 Hz for ACV and 50 ~ 60 Hz for ACA

  A further, slightly related, question is Is this actually a True RMS meter?  That does a proper True RMS calculation?  I ask because the specs for ACV and ACA say "Non-sinusoidal wave counts add error by crest factor."

  Thanks, Brian.

[joeqsmith]

I've never measured it but Google search shows 400Hz.  What did you measure? 

[Martin72]

Hi,

This is what the german ut210-e manual describes :

"Frequency measurement up to 60 kHz (V.F.C. = Voltage Frequency Conversion, e.g. for electronic
actuated drives)"

[joeqsmith]

Hi,

This is what the german ut210-e manual describes :

"Frequency measurement up to 60 kHz (V.F.C. = Voltage Frequency Conversion, e.g. for electronic
actuated drives)"

Using the same clamp in my previous post:
https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/msg3155612/#msg3155612

In the standard mode, I measure the 3dB point at 2.8KHz.   I typically suggest they are good for about 2KHz.   With VFC active, the 3dB point moves down to 660Hz.   I'm sure some are better and others worse but the 400Hz I found with Google seems to be in the ballpark.

[Brian of Romsey]

Joe,

  Thanks for some definitive information, even if it is just what you've measured.  I've hand annotated my 'documentation' to match. 

  Cheers, Brian.