New TRMS Uni-T UT139C DMM is available now

[Ether]

This meter looks pretty good. Just wondering, in comparison with the UT61E, does it outshine it in terms of usefulness? I understand that both have their pros and cons but does the resolution on the 61E outweigh the 139C's better input protection, NCV, backlight, auto power-off etc. ?

By the way, I'm asking because I'm looking to get another meter to complement my Fluke 73 III that has been really reliable but somewhat lacking in features so I appreciate any help. 

[Creep]

Totally depends on what you want to use it for. If your thinking of probing mains a lot etc. then you probably want to go for the 139C. If your only working on the bench, then UT61E is your best bet I would say.

[Ether]

Yeah, I think what you said made sense.

I think I'll probably get a UT61E for the bench and use my Fluke for any  high-voltage work.

After all, the 22000 count is really appealing to a guy with more than a few 6000 count meters.

[Wytnucls]

Don't rely on the last digit of the 61E.
The meter doesn't have an external voltage reference and in my experience drifts way too much for a 4 1/2 count meter.

[Ether]

Then Wytnucls, in light of that, would you recommend the 139C over the 61E, seeing that the last digit is useless anyway?

[Wytnucls]

I guess so, as I would happily trade my 61E for a 139C. But compare features and get the one that fits your needs better.

[Legit-Design]

This meter looks pretty good. Just wondering, in comparison with the UT61E, does it outshine it in terms of usefulness? I understand that both have their pros and cons but does the resolution on the 61E outweigh the 139C's better input protection, NCV, backlight, auto power-off etc. ?

I wrote elsewhere on the NCV function:

Having used UT139C I wouldn't put much if any value on having NCV, in my opinion it's way too sensitive for all kinds of fields. I actually went and got cheapest non contact volt meter pen from the store, it was 5€ and it can light led on which europlug hole is the live one. First pen I got didn't work a real piece of crap, even tried another battery, went to the store and got it exchanged and they even let me test the new was functional. Of course a meter is way too big to show anything with such accuracy, but UT139C picks up fields from all over the place. For example just measured full bars 80mm from my computer display that has ccfl backlight. If I bring my hand to closer to the meters sensor it will drop to 2 bars. A real non contact voltage pen doesn't react to display in any way. Also UT139C seems to pick up voltages from just simple metal surfaces around the room. UT139C thinks my headphone cable while only connected to computer has 4 bars worth of voltage, and I'm not even playing anything through the headphones can even disconnect and leave only the cable and it still thinks there is big voltages on the cable. Real cheapo voltage pen doesn't show anything for the headphone cable. Or maybe the unit I received is faulty and I opened mine and posted some pictures so it doesn't even have warranty anymore, or maybe it never had warranty since I bought it ebay china. I wouldn't advice anyone to trust their lives on UT139C NCV function, it's flaky and unreliable. If properly used a cheap non contact voltage pen might be something to rely on.

still just my opinion and experiences, your mileage may wary. the youtube review/teardown by a forum member only showed NCV when close to mains wire, and mine works just the same way with mains voltages, but it's the other things I'm worried about.

[lpc32]

...backlight...

The light turns off automatically after 15 seconds, and to turn it on you need to hold the button for 2 seconds, so I find it rather useless. Unless there's a hidden way to configure it to stay.

[Ether]

I hope I'm not hijacking this thread by asking this, but does anybody reckon that the dt-2843r ot the dt-4000zc might be of better value in comparison to the 139C?

[n33d]

Hi All,
I am new to DMM stuff and UT139C is my first DMM. Just got it yesterday.

while playing with the meter, i've noticed that it behaved strangely when i test for resistance. i used my test lead and clamp them together, it showed 0.00 Ohm(expected 0.1 or 0.2ohm) but when i switched to continuity test, it showed 0.02. Test done on other wires and the pattern is consistent. Always +0.02 Ohm when switched to continuity

Is this "auto-zero" feature from uni-t???

[Wytnucls]

Resolution is 0.1 Ohm on the lowest 600.0 Ohm range with an accuracy of 1%+2, so assuming your test leads have a true resistance of 0.2 Ohm, any reading between 0.3 and -0.1 Ohm would be within specs.

[lpc32]

does anybody reckon that the dt-2843r ot the dt-4000zc might be of better value in comparison to the 139C?

I guess that depends on your requirements. Look for features you must have and see which meters match.

[Lightages]

The main differences to consider IMHO:

DT2843R has True-RMS with DC, UT139C appears to be True-RMS AC only
DT2843R has a slow continuity test, UT139C is fast
DT2843R has limited input protection, UT139C has much better input protection
DT2843R does not have a non-contact voltage detector, UT139C has NCV
DT2843R has a better made temperature probe, UT139C is a simple welded bead end.
DT2843R 4000 count, UT139C 6000 count

DT4000ZC is close to the same as the DT2843R, but has PC connection and software.

Conclusion:
Need a safer meter, UT139C. Need fast continuity, UT139C or DT-4000ZC. Need NCV, UT139C.
Need True-RMS +DC, DT2843R.
Need PC logging, DT-4000ZC.

I would recommend the UT139C to most people from what I have seen. I have a DT2843R and it is a very good meter for the money too, but I think the UT139C edges it out for most uses.

[lpc32]

Don't forget that value also includes price.

And there may be some differences in accuracy.

[jarvis]

Low AC bandwidth (1.5kHz) TRMS of UT139C seems not accurated for square wave or higher crest factor waveform even it is lower frequency.

[Wytnucls]

AC bandwidth is 1kHz. Crest factor up to 3.0 for low voltage signal which has to reach at least 5% of the range for accuracy.
That should cover square, triangle and half rectified sine waves.

[Ether]

Thanks to everyone for the replies. I finally settled on a UT139C over the Digitek offerings after comparing the specs again. Personally, I think that the poor-quality temperature probe/thermocouple included can probably be replaced, albeit at an additional cost. The deal-breaker for me was the continuity. Slow continuity is a pain to work with and I would happily trade the True-RMS DC for fast continuity. The NCV and 6000 counts just sweetened the deal. I'll post my impressions after receiving it but from what it looks like, it looks pretty promising. By the way, anybody knows what the V.F.C means. I'm guessing variable frequency something, correct me if I'm wrong.

[HiTech]

If they skimped and lied bout the rating again then this would be a potential bomb ready to go off in your hand.

Don't worry about it .... after all, the old saying "you get what you pay for" is very often true. At the end of the day, it's still a $50 DMM from a company that probably trained field mice to assemble it to maintain a profit margin.

[lpc32]

Another point: the UT139C's temperature resolution is only 1C.

VFC, the manual says, is for variable frequency voltage. Maybe someone else can shed more light.

[Lightages]

The VFC function is supposedly a high roll off filter to reduce noise on the measurement from switched variable frequency motor drives.

[Legit-Design]

Another point: the UT139C's temperature resolution is only 1C.

Also the temperature is all over the place when multimeter comes from the freezer, yes I tested mine, left it in the freezer and took it in the room temperature. It took a long time to warm up and start to show up reasonable temperatures. Maybe this is because there is no cold junction compensation? Or the temperature measurement is just crap. Might be a problem in some places where it is actually so cold it snows in the winter, and some people might want to use it to troubleshoot their car or something. But if used in normal room temperatures it might be of some use.

Having 2x AA batteries (UT139C) in a multimeter is a huge plus over single 9V battery (UT61E/D). Now that I've got to use mine and seems like the 9V batteries are flat way too soon. More time without battery warning icon means more measurements that are most likely accurate.

[Ether]

I just received my UT139C. Haven't done any extensive testing yet but I must say, the construction quality is excellent. I especially liked the sturdy holster which would easily protect the meter from a fall off the bench. Backlight is acceptable as well and the selector wheel is nice to turn and relatively "clicky" but some might consider it too mushy. Included probes are acceptable but I recommend Fluke TL75 leads. 

I tried to replicate Legit-Design's NCV problem. Unfortunately, I couldn't get it to go off at my earphones (plugged into a computer). However, I noticed that it works better with the holster off but I still wouldn't trust my life on this. Useful in a pinch but if you're doing high voltage work frequently,  invest in a proper voltage pen. 

The temperature probe is pretty cheap and only goes up to 230 celsius if I'm not wrong but this meter is only good for ballpark measurements due to its low resolution.

For a first impression, that's more all or less all the annoying flaws I spotted. Don't get me wrong though, this is an excellent meter for the price point and the features/cost ratio is superior to practically every other meter at this price point. Also, the input protection is properly designed with the standard MOVs and PTCs (600V) so this would be a better option for beginners as it is less likely to spontaneously combust if you screw up. Fuses are properly rated at 600V and are HRC fuses.

That's about it but I would be happy to try any other tests that others might suggest. 

[Monkeh]

However, I noticed that it works better with the holster off but I still wouldn't trust my life on this. Useful in a pinch but if you're doing high voltage work frequently,  invest in a proper voltage pen. 

If you'd trust your life to a voltstick, you're an idiot. They are for locating wires, not determining if they're dead or not.

[Ether]

Perhaps I didn't phrase that correctly, but essentially, knowing where the wires are is pretty important if you don't intend to live a shorter than average life. Determining whether the wires are dead or not is a different matter so you do have a point there Monkeh.

[gigahertz]

Gents,

On your web site is mentioned “Optional AC/DC 60A current clamps in different models to measure current up to 60A(1mv=1A)”;
Where can I found the current clamp? Has it a separate ordering code?

Regards!