A look at the Uni-T UT210E - Page 1
Forum section: electronics / testgear

author: Maxlor
author_rank: Frequent Contributor
timestamp: November 29, 2014, 08:28:44 pm
content: I recently picked up a Uni-T UT210E clamp meter. It's an interesting device for electronics use, since its clamp can measure DC current, it has a 2A range which gives you 1 mA resolution, and it only costs 35 USD.I've looked at many different clamp meters, and typically they come with one or more of these limitations:They don't measure DC current, only AC current. Sometimes they claim DC current capability, but upon closer inspection you notice it's using the leads, no the clamp.They only work with high currents. The lowest range on many devices is 20A or 40A, which gives you 10mA resolution.They are expensive, often well into the 3 or even 4 digit USD range.So what do you get for $35 with the UT210E? The meter comes in a soft case and some leads, whose shroud is detachable. The leads are Uni-T branded and claim Cat IV 600V with the shroud on, and they're pretty crappy overall. Very inflexible cables that tangle easily. Fortunately, for the primary intended use of the meter, the leads aren't required.The clamp claims Cat II 600V and Cat III 300V, and opens to about 16mm, which is plenty. The movement has no play and feels solid. Between 15N and 20N of pressure is required to open the clamp.Overall it's a small device that fits well into the hand. The display is mounted in such a way that it can be awkward to read, either because it's at an angle when pointing the clamp away from you, or because you're covering it with your hand when holding it with your right hand and your thumb on the clamp opening mechanism. Larger clamp meters have the display at the very bottom for this reason I guess.The device does feel very solid in the hand, no flex or creaking. The small form factor helps give it stability. Materials are the same as on other Uni-T multimeters I've seen, it's fine. The red parts on the case (but not the clamp) are rubberized, not enough to provide shock protection though. While it certainly doesn't seem fragile, dropping the meter is probably a bad idea since the ferrite the clamp is made of might shatter.So lets peek inside! It takes two AAA batteries, and the battery screw goes into a metal insert. This is good since in current measurement modes it consumes about 6mA (12mA with the backlight), so the batteries would last less than 200 hours. In the other modes it's only 2mA, but those won't see much use.The back half of the case is held by two self-tapping screws into plastic. Not an issue, since there's not much reason to open the device, there are no fuses (all current measurement modes use the clamp.)Inside the device there are a *lot* of passive components, in particular there's a whole bank of capacitors in the lower right. Input protection seems fair enough for the input jacks. I have no idea what's required for the clamp though, if anything at all. Even when measuring high currents, there's nothing dangerous going inside the meter I guess though? Experts, please speak up.There are two larger chips. The one on the left is aTI OPA4330quad opamp (Markings: TI O4330A 44K G4 AN50), the one on the right is theHycom DMM Chip(Markings: Hycom H203 DTM0660L R3MR81A)Let's test it! Here's my test setup. Basically I had my PSU output a current in constant current mode, it went through the clamp and by BM257, the latter I used to check against. Accuracy of the UT210E in DC current mode is 2% + 8 counts in the 2A range, and 2% + 3 counts in the 20A range.As with any clamp meter in DC current mode, zeroing is important but can be finicky. I rested the meter on the table and tried not to move it when changing ranges or pressing the zero button. This way, zeroing was good for up to a minute, at which point it started to drift more than 2 or 3 mA. When holding it in your hand, you can expect to zero it for every single measurement if you care about single milliamps. With higher currents, the magnetic fields of the meters environment don't matter so much so you get more repeatable measurements. One way to increase the measured current btw is to loop the cable through the clamp several times, you'll just have to divide the reading by the number of loops.Rotating the meter introduces errors of several dozen mA.Cable position within the clamp does not matter btw. As long as the cable goes through the clamp, you get the same measurement.On to the measurements!BM257 - UT210E08.42mA - 0.009A17.89mA - 0.019A48.86mA - 0.049A097.6mA - 0.097A497.8mA - 0.494A1.990A - 1.985A4.996A - 04.97AAs you can see, the two meters match up well, better than I expected! I tested voltage and resistance too against some precision references and precision resistors. It read 0.4% high on average in voltage mode (worst: 0.47% or 5 counts) and was generally bang on in resistance mode (worst: 0.2% or 2 counts.)Screen update rate is unusually fast for Uni-T at around 4 updates per second. Unfortunately, other things are slow: the latched continuity tester is usable, but certainly not fast. Resistance autoranging is slow. Reading current with the clamp is also a tad slow, it usually a second or two for the value to come up to the right area, and then 2-3 seconds more for the last digit to stabilize, so current isn't instant.In voltage mode, you get no overshoot, but usually have to wait 0.5-1 second to get a reading because of the autoranging (which you can't disable). It shows you ---- while it's doing that, and then gives you a stable value, I like that.Non-Contact voltage measurement shows you whether you have a live wire, and it works well. The shape of the meter makes it clear where the sensor is (top of the clamp under the little bump); this can be frustrating with classic multimeters. It reacts quickly in about half a second, and you get a display on the screen, a flashing LED and the buzzer that beeps at you.I didn't test any AC stuff.Overall, for the price ($35), I recommend this meter for electronics hobbyists. It's cheap at $35, and you get usable DC mA readings (if you use it right, i.e. no moving after zeroing), without having to cut any wires. I wouldn't suggest it as a first or second multimeter, but after that, go for it!

author: SkyMaster
author_rank: Frequent Contributor
timestamp: July 03, 2015, 01:09:06 am
content: Maxlor,Do you have any update for us? It was more than 6 months ago that you posted your very detailed initial review of the UNI-T UT210E.

author: Circlotron
author_rank: Super Contributor
timestamp: July 18, 2015, 12:35:18 pm
content: I went and got one after reading this thread. BigClamped it around everything I could find. Solar panels making 3.85 amps @ 250VDC. Car running with headlights, a/c, heater fan and rear demister showed 52 amps going through some fat wire into the fusebox. In particular, I have a 33V 30A DC supply that is great for charging car batteries but if you go over current it will trip out and switch off. Now I can wind the voltage up gradually and set it so the current doesn't go over and shut off.

author: jancelot
author_rank: Regular Contributor
timestamp: July 18, 2015, 02:56:59 pm
content: Great that UNI-T hardware comes with its own case, Brymen multimeters are intended to carry loose I guess.

author: Maxlor
author_rank: Frequent Contributor
timestamp: August 11, 2015, 09:37:14 pm
content: Quote from: SkyMaster on July 03, 2015, 01:09:06 amUpdate? What more do you want to know? The only thing I can add now is that I periodically checked its DCV and Resistance readings against a reference for a couple of months to see whether it'd drift like some other Uni-T meters. It doesn't, I get the same reading every time.Other than that, I don't use it terribly often, mostly when trying to figure out what some battery is doing without having to disconnect it. In those instances, it's certainly a nice to have tool.

author: SkyMaster
author_rank: Frequent Contributor
timestamp: August 12, 2015, 02:46:19 am
content: Quote from: Maxlor on August 11, 2015, 09:37:14 pmYes I was looking for your long term satisfaction level; thank you for thatYour original post convinced me to order one. Being able to measure DC current with a clamp meter is very convenient.

author: Circlotron
author_rank: Super Contributor
timestamp: August 13, 2015, 04:02:11 am
content: Quote from: Maxlor on November 29, 2014, 08:28:44 pmWhen I first got mine I put a pair of AAA NiMH batteries in it because that was all I had lying around. On the 2 amp range, after zeroing, it would drift maybe 40 mA in 1 minute, then zero again and it would drift again. Then just today I replaced the batteries with normal alkalines and unexpectedly the drift has reduced by a factor of 10 or better. The alkalines would be a higher voltage than the NiMHs I used so that may be a factor to consider. The low battery indicator was not coming on though.

author: salil
author_rank: Regular Contributor
timestamp: September 20, 2015, 12:35:11 am
content: How does the UT210E compared to the bazillion other clamp meter models Uni-T offers? Are there any comparable models made by Uni-T that offer non-contact DC current measurement?http://www.uni-trend.com/en/product/list_318_1.html

author: Maxlor
author_rank: Frequent Contributor
timestamp: September 20, 2015, 12:43:06 am
content: There's the UT211B which costs nearly 3 times as much. None of their other clamps have 1mA DC resolution.

author: salil
author_rank: Regular Contributor
timestamp: September 20, 2015, 12:50:47 am
content: Quote from: Maxlor on September 20, 2015, 12:43:06 amThank you, you saved me some time.

author: Lightages
author_rank: Unknown
timestamp: September 20, 2015, 02:07:35 am
content: forget what I said

author: max666
author_rank: Frequent Contributor
timestamp: October 07, 2015, 01:51:22 am
content: Thanks for the review, Maxlor.I've decided to order one as well.

author: amirm
author_rank: Regular Contributor
timestamp: October 07, 2015, 02:44:09 am
content: My thanks also for the review. I bought one for my toolbox around the house and really like it!

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 07, 2015, 08:32:37 am
content: Thank you as well for the review, looks like a great clamp meter for the money!

author: Macbeth
author_rank: Super Contributor
timestamp: October 07, 2015, 08:51:59 am
content: I always associated clamp meters with AC current, and high currents at that like in mains stuff so never bothered getting one. Measuring relatively low DC currents makes this a must have - especially when fault finding a cars wiring loom or stuff like that.

author: Kalvin
author_rank: Super Contributor
timestamp: October 08, 2015, 05:19:22 pm
content: Thanks for the review! Just bought one.

author: sequoia
author_rank: Unknown
timestamp: October 09, 2015, 11:44:04 pm
content: If the CAT ratings were "real", shouldn't there be some 600V (or higher) rated fuses at minimum?Seems like there is just two small poly fuses (PTCs) instead.Any idea what the three blue components next to the PTCs are? They seem to be labeled DT1,DT2,DT3 ?

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 10, 2015, 12:50:58 am
content: Quote from: sequoia on October 09, 2015, 11:44:04 pmI'm guessing they're MOVs (metal oxide varistors), but I'm not sure

author: Lightages
author_rank: Unknown
timestamp: October 10, 2015, 01:00:45 am
content: Think about it..... A clamp meter doesn't measure current with the test leads........

author: R_G_B_
author_rank: Frequent Contributor
timestamp: October 10, 2015, 02:07:03 pm
content: interesting in the manual of this clamp meter it uses the term virtual true RMS. Yet it states on the clamp meter it is true RMS so which one is it?R_G_B

author: Maxlor
author_rank: Frequent Contributor
timestamp: October 10, 2015, 08:42:59 pm
content: Not sure what the virtual's supposed to mean, in my tests it gives TrueRMS values in both voltage and current modes. Bad translation, I'm guessing?Btw, Conrad is now selling these under the name Voltcraft VC-330.

author: SLJ
author_rank: Frequent Contributor
timestamp: October 10, 2015, 11:06:36 pm
content: Looks interesting. I needed something for the garage so I just ordered one.

author: rommo
author_rank: Newbie
timestamp: October 17, 2015, 10:17:47 am
content: Hello, included with the button held down blue and yellow, huddled all settings become vrat.Servis manual for configuring found.

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 17, 2015, 10:35:12 am
content: Quote from: rommo on October 17, 2015, 10:17:47 am

author: rommo
author_rank: Newbie
timestamp: October 17, 2015, 10:42:36 am
content: Press the blue and yellow button, and turned on. Reset calibration.