EEVblog® Electronics Community Forum
Products => Test Equipment => Topic started by: sky666 on September 29, 2020, 09:52:44 am
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Hi guys,
I know you are already tired of questions about the UNI-T UT210E clamp meter but I recently bought a new model UT210E PRO version. According to several reviews of the standard model, I could see that in the DCA area it shows a value that deviates slightly from 0.000A without load and without the zero button being pressed. In my case the value is around 0.220 - 0.300A. After pressing zero the button varies between 0.000 - 0.005A without any movement of the device or close external magnetic field. Do you think this is normal?
[attach=1]
Another thing that is important to me is that the sensor on one side of the clamp looks pretty scratched. It can be seen in the picture. I would be grateful if any of you could take a picture of the sensor on his clamp meter just to see if such scratches are normal.
[attach=2][attach=3]
Thank you
Edit: It does not have to be a picture strictly of this multimeter, it can be from the sensor of any clamp meter.
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I've never seen a "pro" model, even the UNI-T site not mention it, maybe a counterfeit? But, I'm not sure, not a fan of UNI-T or following with attention their products.
https://www.uni-trend.com/html/product/General_Meters/digitalclampmeters/UT210_Series/UT210E.html (https://www.uni-trend.com/html/product/General_Meters/digitalclampmeters/UT210_Series/UT210E.html)
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The pro model has some advantages. Btw. i noticed a similar behavior at my normal UT210e
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Without a properly closed magnetic circuit (i.e. a different type of clamp) any clamp meter measuring in the ~2A range will see some offset due to the Earth's magnetic field.
This is exactly what the zero button is for, though even with this you need to be careful to not change the orientation etc (ideally zero with it around an unpowered conductor, or if not possible move the least amount when clamping).
Edit: checked mine and the offset before zeroing is a fair bit less than the value you are seeing. Maybe yours needs a degauss?
Also, the PRO seems like a _very_ minor upgrade unless you regularly want to use the probes to measure frequency.
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Scratching could be them grinding the two edges flat to meet flush.
The pro model has some advantages. Btw. i noticed a similar behavior at my normal UT210e
Well, according to that chart it only has the one advantage that it measures frequency. Seems kind of pointless for most people.
edit: I'm blind.
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I'm not sure what brand/model mine is at work, but it has nearly the same offset when powered on.
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Scratching could be them grinding the two edges flat to meet flush.
The pro model has some advantages. Btw. i noticed a similar behavior at my normal UT210e
Well, according to that chart it only has the one advantage that it measures frequency. Seems kind of pointless for most people.
edit: I'm blind.
I do not believe because the device is brand new, I got it a few days ago. The opposite side is shiny plastic and is more susceptible to scratches. There are no traces of it. Apparently the scratches occurred during the installation of the sensor in the factory unless someone changed something after that.,
Capacity measurement is also increased to 60mF.
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Without a properly closed magnetic circuit (i.e. a different type of clamp) any clamp meter measuring in the ~2A range will see some offset due to the Earth's magnetic field.
This is exactly what the zero button is for, though even with this you need to be careful to not change the orientation etc (ideally zero with it around an unpowered conductor, or if not possible move the least amount when clamping).
Edit: checked mine and the offset before zeroing is a fair bit less than the value you are seeing. Maybe yours needs a degauss?
Also, the PRO seems like a _very_ minor upgrade unless you regularly want to use the probes to measure frequency.
It is true that the offset is almost always present but the fact is that there are many reviews on YouTube where it can be noticed that the offset is not greater than 0.010A. It seems more likely that some devices are more or less magnetized.
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The pro model has some advantages. Btw. i noticed a similar behavior at my normal UT210e
From where it's that table? Uni-T site or something else?
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From where it's that table? Uni-T site or something else?
From the product page of the official Uni-t aliexpress store.
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From the product page of the official Uni-t aliexpress store.
Very strange, the page of the brand haven't this model, not offer this version at all. I'm interested in this model only if it is real, but I not find it in any of the usual confident pages that I look. This is announced as the official store on aliexpress https://es.aliexpress.com/store/3095007 and I can't found the pro model, only the standard model is announced. Can you give me the link to the official store? Thanks in advance
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... and I can't found the pro model, only the standard model is announced. Can you give me the link to the official store? Thanks in advance
right here:
https://www.aliexpress.com/item/4001222938892.html? (https://www.aliexpress.com/item/4001222938892.html?)
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So for comparison my meter looks as seen in the following pictures. Jaws are a little dirty but not scratched up. When new it the offset was a bit higher, but I've managed to magnetise it then degauss it a couple times since.
Personally I would have a go at degaussing the clamp (even twirling a magnet on a stick around the jaws while moving slowly away might do the trick) and wouldn't worry about it too much as long as the offset can be zeroed out - some offset is unavoidable (e.g. mine gets about 4x worse than shown in the pic depending on orientation vs the earth). Also worth a quick check vs a normal meter.
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It's a cheap meter, and it's got a DC current range with 1mA resolution.
Hall sensors are inherently quite bad at drift specifications, and added to that you also have residual magnetism and hysteresis in the clamp itself.
Changes on the display when the meter is rotated are due to the earth magnetic field and this means that it's resolution is about as sensitive as you can possibly get with this class of meters.
So a bit of drift for this class of meter is normal. Just be happy you've got a 2A DC current range at all.
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So for comparison my meter looks as seen in the following pictures. Jaws are a little dirty but not scratched up. When new it the offset was a bit higher, but I've managed to magnetise it then degauss it a couple times since.
Personally I would have a go at degaussing the clamp (even twirling a magnet on a stick around the jaws while moving slowly away might do the trick) and wouldn't worry about it too much as long as the offset can be zeroed out - some offset is unavoidable (e.g. mine gets about 4x worse than shown in the pic depending on orientation vs the earth). Also worth a quick check vs a normal meter.
Thank you for taking the time for the photos.
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It's a cheap meter, and it's got a DC current range with 1mA resolution.
Hall sensors are inherently quite bad at drift specifications, and added to that you also have residual magnetism and hysteresis in the clamp itself.
Changes on the display when the meter is rotated are due to the earth magnetic field and this means that it's resolution is about as sensitive as you can possibly get with this class of meters.
So a bit of drift for this class of meter is normal. Just be happy you've got a 2A DC current range at all.
You may be right but the fact that many of the devices are quite "normal" may mean that some of the devices are inadequately stored. And that this problem is not due to the quality of the device. I mean those devices with offset up to + - 0.020A.
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So for comparison my meter looks as seen in the following pictures. Jaws are a little dirty but not scratched up. When new it the offset was a bit higher, but I've managed to magnetise it then degauss it a couple times since.
Personally I would have a go at degaussing the clamp (even twirling a magnet on a stick around the jaws while moving slowly away might do the trick) and wouldn't worry about it too much as long as the offset can be zeroed out - some offset is unavoidable (e.g. mine gets about 4x worse than shown in the pic depending on orientation vs the earth). Also worth a quick check vs a normal meter.
Can you tell me please where did you buy it? From a local store or online store in Europe?
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I initially had NiMH batteries in mine and then I changed over to normal alkalines and with their slightly higher voltage it seemed to drift less. Might be my imagination, but that's the impression I got at the time.
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I tried with brand new Duracell, no change.
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I recorded video of process of resetting to zero of the current indications in the DC mode at UT210E. This method allows to reduce residual indications in the mode of measurement of a direct current (DC 2A Dotless, 2A,20A,100A) without the need for EEPROM correction without the programmator. Thanks of kDnZP from a Russian-speaking forum!
ATTENTION! To do only if there is a backup copy of EEPROM!
1. To switch off device.
2. To clamp HOLD+SELECT and to switch to the "resistance, ring-up, diode, condenser" mode.
3. To see a text of "CAL", to release the HOLD+SELECT buttons
4. To wait. To wait long and not to hurry. To wait so far there will pass all self-tests until squeaks, then still to wait and wait for the moment when there are changing indications of the millivoltmeter. I.e. when the self-test will be completely passable, it will take ~ 2-3 minutes.
5. Further it is possible to switch the selector on 20A, to press the ZERO button and to nullify indications. At the same time the instrument in hand not to hold, give time for that that indications calmed down, to place the instrument where least of all el./magn. noises and the more so far away from magnets.
6. To switch the selector on 2A and to repeat the same as in point 5.
7. If necessary it is possible to modify values on other interesting ranges
8. On the end of calibration - to transfer the selector to "OFF"
9. To switch on ut201e and to check indications, if necessary - to repeat.
The link to video which explains this process.
https://yadi.sk/i/bu8eS8uF3ZfK3E
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Interesting. In this case, if there is any remaining magnetism on the clamp, the recalibration does not remove it. Only calibrates the current value to zero. The question is whether the other measurements remain the same. Maybe I'll try, I'm just scared of:
"ATTENTION! To do only if there is a backup copy of EEPROM!"
:-BROKE
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sky666
I have specifically highlighted this warning in bold text!
If you do not have a copy of your device's EEPROM, then there is a very high risk of damaging the contents of memory cells if unsuccessful actions are taken. This dump is unique to each instrument and is calibration using standards at the factory. Bear this in mind, I warned. ;) In addition, a backup copy of the EEPROM can greatly help in restoring the operation of the device if a failure occurs or the cells of the 24C02 (08) microcircuit are damaged. This situation can happen with any device in this category and has already happened to some owners of multimeters based on the DTM0660 processor and its analogues.
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OK, thanks!
... But, how do one make a copy of the EEPROM then? And restore it, if need be?
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... But, how do one make a copy of the EEPROM then? And restore it, if need be?
https://youtu.be/Vj6b-clYTis?t=221
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I wonder what's the CHIPSET? It's the same as the "regular" UT210E? DM1106EN ?? If yes, you can hack it from 2,000 counts to 10,000 counts.
Maybe your "UT210E Pro" firmware could be useful to unlock the Frequency e more Capacitance range in the regular UT210E.
Please, could you check this out?
https://thearduinoshed.wordpress.com/2020/04/13/uni-t-ut210e-current-clamp-hacking/ (https://thearduinoshed.wordpress.com/2020/04/13/uni-t-ut210e-current-clamp-hacking/)
https://www.youtube.com/watch?v=fX-Fhq9R4uY (https://www.youtube.com/watch?v=fX-Fhq9R4uY)
https://www.youtube.com/watch?v=PghlJbbj6pA (https://www.youtube.com/watch?v=PghlJbbj6pA)
https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/msg1423248/#msg1423248 (https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/msg1423248/#msg1423248)
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Yes, the chipset is the same as the UNI-T 210E. The same pcb, rev.1 also. I cannot find any difference at least from the upper side.
I am planing to do this soon, I just need to get the right equipment first.
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I am planing to do this soon, I just need to get the right equipment first.
Did you check this link?
https://thearduinoshed.wordpress.com/2020/04/13/uni-t-ut210e-current-clamp-hacking/
You don't need an "AVR Programmer", you can use the "SDA and SCL" connections.
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I will buy the EEPROM USB Programmer first anyway. The EEPROM version can be seen in the picture. I hope this type of AVR programmer works.
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Hello,
This new UT-210E Pro can measure frequencies and see more capacitance. The UT-211B with 6000 counts can this.
I hope it can be hackable like classic version.
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Hello,
This new UT-210E Pro can measure frequencies and see more capacitance. The UT-211B with 6000 counts can this.
I hope it can be hackable like classic version.
EEPROM can be programmed, I cannot see any significant changes.
We'll see.
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Hello,
This new UT-210E Pro can measure frequencies and see more capacitance. The UT-211B with 6000 counts can this.
I hope it can be hackable like classic version.
Any reason for the UNI-T UT211B to cost around 2x the price of UT210E Pro, since they have basically the same features? (the only significative difference is 6k vs 2k counts, but you can hack the UT210E to up 10k counts)
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The UT-211B are overpriced. No standard fuses for cost.
But he can measure current at 6000 counts in mA when zeroing offset display.
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Hi sky666,
could you please unscrew the back cover and take some photos with components ids and put them here?
so that we can compare your version of the meter "UT-210E PRO" with model "UT-210E" (without PRO)
Have you tried to improve your meter?
Best regards,
Darek
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Hi sky666,
could you please unscrew the back cover and take some photos with components ids and put them here?
so that we can compare your version of the meter "UT-210E PRO" with model "UT-210E" (without PRO)
Have you tried to improve your meter?
Best regards,
Darek
here is my uni-t ut210e
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Any reason for the UNI-T UT211B to cost around 2x the price of UT210E Pro, since they have basically the same features? (the only significative difference is 6k vs 2k counts, but you can hack the UT210E to up 10k counts)
The UT-211B advertises 0.1mA resolution and can potentially measure such low currents, which makes it "perfect for anyone requiring high precision and accurate results when working with electronics, such as troubleshooting solar power systems current load, electrical cars, etc.". If you dig into the product manual, however, you discover its high resolution (and stated accuracy) is only for AC. Was it meant to have 0.1mA resolution on DC? I tend to the notion that measuring low DC currents with a clamp-on meter is not that easy.
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Hello,
Are you hacked your Pro version to 9999 counts ? Possibility to active temperature measurement ?
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I apologize for the delay. I got the AVR programmer some time ago, the first order was lost during shipping. Honestly, after so much waiting, I changed my mind. Somehow I lost my interest in modifying the AVR programmer for now (due to 5V voltage).
These are the pictures from the device.
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Here is my UT210E PRO.
Just out of the box it shown DC current offset about 0.022 mA. But when I played with short circuit measurement of 0.04 Ω wire I caught a drift about 0.2-0.5 Amps.
I investigated the issue and found that it happens due to a capacitor on the output terminals of my PSU. The capacitor is 532 uF and when I connect wire it cause high current pulse which value depends on capacitor voltage charge. And it looks that this pulse cause clamp magnetization. Because when I apply this pulse in reverse polarity it leads to reverse current offset to opposite sign.
So, I found the way to demagnetize clamp. I just apply short circuit pulse (in reverse polarity to current offset) and look at current offset change. Then reduce voltage for a little on the PSU output and apply pulse in reverse polarity. And retry until current offset will be minimized to zero.
I found that it's better to put clamp meter on wire when the current already flows through the wire. Because if you switch on power with clamp meter it may cause high current pulse and lead to magnetization of the clamp meter. Switch with 0.5 Amp pulse almost doesn't affect current offset. But switch with 70-100 Amps leads to some current offset and requires demagnetization.
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Is that normal, that I get different readings when measuring direct and returning DC current of a circuit? It always shows lower current when negative. Surely, I zero the meter before taking measurements.
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FYI the UT210E Pro has the EEPROM AT24C08A which has 1Kb of memory instead of the AT24C02A which has 256b or memory.
attached is my stock dump. and how i connected the programmer. the clamp meter was on 2A mode,
[attachimg=2]
[attachimg=3]
[attachimg=4]
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Scratching could be them grinding the two edges flat to meet flush.
Well, according to that chart it only has the one advantage that it measures frequency. Seems kind of pointless for most people.
edit: I'm blind.
Apologies from another blind person but could someone kindly point out what other technical differences there are between the UT210E and the UT210E Pro than the Frequency measurement ? I've gone up and down the image in post #2 but cannot see anything else ?
Thanks,
Boo
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Hello friends,
if anyone here has the original bin file for the 210E Pro, please send it to me.
[email protected]
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Hello friends,
if anyone here has the original bin file for the 210E Pro, please send it to me.
[email protected]