Possible noob question about UNI-T UT210E clamp meter - Page 1
Forum section: electronics / testgear

author: lumpy
author_rank: Newbie
timestamp: May 07, 2020, 04:13:50 am
content: I recently got the UNI-T UT210E and I am not sure whether the product is defective or my brain is defective.I haven't been able to get the actual clamping, current measurement part to work (everything else works) I look up videos and such, and it appears you just set it to the proper 2/20/200A part on the knob and then put the clamp around any current carrying wire. When I do this, the display shows some tens of milliamps while opening the clamp and turning it around but it is always 0 or very near 0 when I hold it still, even when around something I know has current. I tried my computer power cord, fan cord, some wires on a breadboard circuit I knew had current because it was reading as such on an oscilloscope, etc. I tried swapping between AC and DC modes to be sure and it would always be 0.So I assumed it was defective and had it replaced, but the new one I got today is the exact same problem. The chances of this problem happening randomly twice in a row seem so low. So even though I am pretty sure I'm using the meter right, what is the possibility I am doing something wrong? Is it possible that this specific problem is really common for this particular model? I would appreciate any input from others who also own this device- experiences, advice, whatever- I'd really like to be able to measure current without just giving up and buying a different brand...

author: WattsThat
author_rank: Frequent Contributor
timestamp: May 07, 2020, 04:41:38 am
content: QuoteSure sounds like operator error. How did you measure your computer cord? Do you have a breakout cable that allows you to measure just one of the two current carrying wires?I hope you understand that that if you put the clamp over both wires in a circuit, the result is zero current.Edit: now having looked at the product specs, it only reads AC current, not DC. Cheapo clamp-ons don’t do DC.

author: JackJones
author_rank: Regular Contributor
timestamp: May 07, 2020, 05:25:11 am
content: Setting it on DC should not read 0. It should be reading pretty much a random figure due to stray magnetic fields until you zero it. What happens if you set it on DC and you bring a magnet close to it? The displayed figure should start noticably increasing.Also, are you putting it around just a single wire, or both current carrying wires?

author: lumpy
author_rank: Newbie
timestamp: May 07, 2020, 07:42:23 am
content: Quote from: WattsThat on May 07, 2020, 04:41:38 amMy wording was unclear, I never had multiple wires in the clamp. I wrote wires as plural because I tried it in a couple of places but it wasn't necessary information. Also, I'll update main post-- its the 210, not the 201! I should have double checked what I typed in before posting. I don't know what the 201 is, but I know where I bought the 210 (Amazon) says that it is DC compatible

author: lumpy
author_rank: Newbie
timestamp: May 07, 2020, 07:48:40 am
content: Quote from: JackJones on May 07, 2020, 05:25:11 amIt does as you described. It would have a random non-zero reading on DC mode, and when I wiggle it around and pick it up and such it would fluctuation randomly. I meant that: As I understand it, when taking DC current measurements using a clamp you need to hold it horizontally, zero it, and keep it still while taking the measurement every time, and that is what I did, and it would never deviate more from 0 than it would by me mimicking the same actions on a wire I knew to be carrying no current.I also just tried the magnet thing, I do get a consistent current change when bringing a magnet near. Although it depends on the way that I position that magnet, sometimes it increases sometimes it decreases. And to clarify your last point, just a single wire.

author: jfiresto
author_rank: Frequent Contributor
timestamp: May 07, 2020, 08:22:53 am
content: The UT210E I had for a few days, like yours, also wandered quite a bit from stray magnetic fields leaking into the ring. I returned it and bought a Benning CM 11, which is about ten times more consistent and accurate, but also about ten times more expensive. The CM 11 was the least expensive DC clamp meter I could find that achieves ca. 1 mA accuracy and can handle up 10A.

author: lumpy
author_rank: Newbie
timestamp: May 08, 2020, 06:56:08 pm
content: Quote from: jfiresto on May 07, 2020, 08:22:53 amI can't afford that, but thanks for the reply. Perhaps having a cheap clamp meter just isn't a good idea.

author: AVGresponding
author_rank: Super Contributor
timestamp: May 09, 2020, 08:59:05 am
content: It does seem fairly unlikely to get two faulty ones in a row, but not impossible.I had two in a row faulty Maha Powerex battery chargers. I dare say the seller was somewhat out of pocket due to postage by the time the third and working unit arrived!I have a Mastech 2108A which has 10mA resolution, so it is possible to get other cheap DC clamp meters. I've checked it against precision home made shunts, and it's pretty damn accurate.One of the otherpatientsposters in the TEA thread recently got a UT210 and I don't recall him having any problems with it.Could you maybe take some pics of your test setup, and maybe show the current being measured by a normal DMM, but not reading on the UT210?It might help us figure the issue out, as if it is another faulty unit, obviously you need to get on to the seller post haste.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 09, 2020, 09:40:28 am
content: I bought one a while back to see what the good wrap here was aboutand as a small 'how low can you go..?' stand-by/backup to my oversized real TRMS ~LOW~ AC mA clamp tester,in which the UNI-T UT210E clamp meter failed at miserably due to its low bandwidthbut still miles ahead of the small Fluke low AC equivalent many times the priceBUT.. but..I kept it because all the rest of the functions work great, especially the low DC and 2 amp AC current clamp biz for 'normal' AC/DC current clamp workBattery life seems good too, still on the first freebie set that the meter came withIMVHO It's one of the better UT offerings, and a keeperso confirm it's not operator error first (read the manual..) and or get another that works

author: AVGresponding
author_rank: Super Contributor
timestamp: May 09, 2020, 10:05:56 am
content: Apparently it's a common issue, joeqsmith might have a solution for you:https://youtu.be/0lyMiAKfOjU

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 09, 2020, 10:52:00 am
content: try measuring simple wire first, say current in mains (50-60Hz) wire.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 09, 2020, 03:53:00 pm
content: Quote from: AVGresponding on May 09, 2020, 10:05:56 amSorry but I've got nothing. Of the eight or so outside of the two I own that I know of in the wild, three have dropped out because of the switch going intermittent. I've yet to see one DOA.Quote from: Electro Detective on May 09, 2020, 09:40:28 amYou do make some odd posts from time to time. For DC, why would you care? For AC, I suspect most people use it for 50/60Hz so again, I don't see the problem. I'm not sure I have heard anyone have a problem with the BW who is actually using the meter. We knew it was limited to about 2KHz fairly early and it's not like that wasn't made public.After deciding mine needed an analog output for the scope, then I thought it could use a higher BW. More just for the fun of it to test my skills. Without the addition of the analog output, I wouldn't have attempted this.I have used it in a few videos after making these changes, so it has come in handy in a few cases. I'm actually surprised that no one else has taken up the challenge. I was able to coax mine to 100KHz and I'm sure there are people here that could have improved on that.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 09, 2020, 11:32:34 pm
content: Quote from: joeqsmith on May 09, 2020, 03:53:00 pmre"You do make some odd posts from time to time." = guilty as chargedBut perhaps I didn't quite explain why properly enough,leads and fingers crossed I do this timeIIRC it fails/failed? for my usage/application at low current TRMS AC if there is any significant distortion of the source waveform, most likely higher frequencies upwards of 1000hz and beyond, plus any associated harmonics.Verified it wasn't my imagination, or UT product bias, by running the distorted source/s via a 14khz AC bandwith TRMS meter in current hook up mode, and my usual low AC TRMS clamp around either leadand both agreed down to 'almost nothing' ACStill, the UT when clamped on to that set up, does show ~something~ is going on,unlike theludicrous pricedFluke 360 AC leakage clamp meter which seems to only favor a clean-ish AC waveform to work at all.Yes I could/should have scoped to unlock the mystery, but more DIY R+D work I didn't need and did not think it would make the UT any better finding out anyway.So basically the UT just did not have enough 'TRUE' TRMS capability at distorted low current AC for my liking/expectations,whereas the stock Fluke 28-11 multimeter and monster sized mA/uA capable TRMS clamp meter both gave the correct and or same reading.I kept the UT for the DC clamp function, thanks to you with other members' usage reportsand the size!That said, I have been using it for mains AC clamp testing in a pinch too, and no complaints from the 2 amp range right up to 100A,and keeps up with the brand name big boys nicelyWould I buy another? YES, to keep this one companyi.e. a great little general purpose AC/DC clamp meter for the money, but not to be mechanically abused or dropped,or plugging the supplied leads into it and expecting any serious CAT performance