Are UNI-T Multimeters any good?

[TMM]

I wanted to buy the Fluke 87 but ended buying ut71d.

I was in the same situation. I wanted a 87V but couldn't justify the price at the time. I bought a UT71D, and more recently needed a second meter with similar accuracy so I finally bought an 87V.

My 2c about the UT71D:

Pros:
-Out of the box DC accuracy is excellent. Within 3 counts of a Fluke 87V (@20000 count).
-AC accuracy is not too bad either.
-AC bandwidth is excellent (100khz+)
-Peak function is far more useful than an 87V due to the higher AC bandwidth.
-Frequency counter shits on the 87V..., counts higher on the same voltage as the 87V. 60Mhz @ 1Vrms is no problem.
-Capable of AC+DC rms measurement.
-Backlight is very bright and even.
-Datalogging. Implementation is basic but does the job.
-Look and feel is decent for the price.

Cons:
-Backlight can only be enabled for 30seconds at a time.
-No touch hold.
-No averaging capability.
-There seems to be an issue with frequency response flatness when measuring AC. Mine takes a ~3% dip around 25-40khz then over-reads slightly as it approaches 100khz.
-The display update rate in 40000 count is slow (2 updates per second). Autoranging on AC is dog slow and it takes a long time to settle on DC mV and AC.
-You can put it into 4000 count mode via a power-on option which makes it super fast (~7-10 updates per second) however it does nothing to speed up the auto ranging or settling time.
-It displays garbage readings on the display while autoranging
-The resistance measurement must not use the dynamic range of the ADC effectively because only has about 4000 counts of real resolution. This is undocumented and a major trap if you are unaware of it.
-Capacitance measurement is affected by parasitics. And slow.
-Continuity is hopelessly slow.
-It beeps every time you press a button or rotate the selector. Beeping can only be disabled globally (through a menu, about 10 button presses) which silences the continuity beeper and lead/jack alerts as well. I don't like how the 87V beeps on button presses either but at least they give you a power on option to shut it up.
-Flimsy split jacks for voltage/common. Current jacks are a beefier split type which are acceptable.
-Very power hungry. 9mA~ on most ranges = poor life out of a 9V battery.
-Abysmal input protection.
-Calibrated by a myriad of trim pots, so long term stability is going to be worse than a digitally calibrated meter like a Fluke.

It is really like a $50 meter with better resolution/accuracy on voltage/current modes and data logging. All the other functionality (resistance, continuity, capacitance, etc) is poor. It makes a good secondary meter if you already have an 87V or similar, but it will piss you off as your main meter. If you want a serious 40000+ count meter look for a second hand Fluke 187/189.

[retiredcaps]

I wanted to buy the Fluke 87 but ended buying ut71d.

I was in the same situation. I wanted a 87V but couldn't justify the price at the time. I bought a new UT71D, and more recently needed a second meter with similar accuracy so I finally bought an 87V.

For people who live in the USA, an used Fluke 87V on ebay goes about the same price as a UT71D +/- $20 USD depending on your patience level.

I realize for those outside the USA, new Fluke products are significantly higher due to exchange rate, taxes and shipping (including Canada).

[aurelleostean]

TMM, in my opinion, is right about 99.9% and that's because he forgot to mention the DC and AC overshoot. TMM thank you! . Regards, Leo.

[Wytnucls]

-No touch hold.
Few meters have it. Mostly a Fluke feature.

-No averaging capability.
Few meters have it, minor detail.

-There seems to be an issue with frequency response flatness when measuring AC. Mine takes a ~3% dip around 25-40khz then over-reads slightly as it approaches 100khz.
No, tested with Rigol DG1022, tracking is perfect.

Autoranging on AC is dog slow and it takes a long time to settle on DC mV and AC.
No lag on DC mV. Can take up to 10 seconds to settle on mV AC due to true RMS AD626, just like the Fluke with the AD737.
Read this thread: https://www.eevblog.com/forum/testgear/fluke-87v-ac-current-measurement/msg328373/#msg328373

-It displays garbage readings on the display while autoranging
Only while ranging up on AC, 2 to 3 secs for a steady reading. Probably due to AD626 again. DC range change is fine.

-The resistance measurement must not use the dynamic range of the ADC effectively because only has about 4000 counts of real resolution. This is undocumented and a major trap if you are unaware of it.
Not on mine, steading 40,000 count resolution on resistance. Measurement goes up to 400MOhm instead of 50MOhm on the Fluke.

-Capacitance measurement is affected by parasitics. And slow.
You need to elaborate on this one.
Most meters are slow on big caps as it takes time to charge them. Tested with a 2200uF cap, 5 seconds for steady reading, 2 seconds for a 68.3nF cap (40,000 count). Range goes up to 40mF, compared to 10mF for the Fluke.

-It beeps every time you press a button or rotate the selector. Beeping can only be disabled globally (through a menu, about 10 button presses)
6 button presses actually. Long press on 'Range' to enter menu, toggle the same button 3 times to access 'beep' setting, press (-) to stop the beep, press 'Exit'. Setting is kept in memory after shut off.

-Very power hungry. 9mA~ on most ranges = poor life out of a 9V battery.
5mA on resistance and capacitance measurement. 3.5mA on DC volt. 2.5mA on Hz/%. 8mA on volt AC, uA/mA/A ranges. 5mA on diode testing. What is the consumption on the Fluke?

-Abysmal input protection.
PTC, 1000V crowbar circuits on most functions and A/mA sense protection. The latest ones have HRC fuses. I wouldn't call that abysmal. Aurelleostean put 2000V DC on his and it just died with a slight whimper.

-Calibrated by a myriad of trim pots, so long term stability is going to be worse than a digitally calibrated meter like a Fluke.
The upside is that yearly calibration is easy and free with the trimpots.
 
It is really like a $50 meter with better resolution/accuracy on voltage/current modes and data logging. All the other functionality (resistance, continuity, capacitance, etc) is poor.
I don't agree with your sweeping statement, except for continuity which could have been be faster.

It makes a good secondary meter if you already have an 87V or similar, but it will piss you off as your main meter. If you want a serious 40000+ count meter look for a second hand Fluke 187/189.
Few meters are perfect and the 187/189 is not one of them. Horrendous battery life and read the thread about leaking capacitors.
The Fluke 87v is a 6000 count meter with a higher resolution available on all ranges, except capacitance, frequency and peak hold.

[aurelleostean]

Hello!  I got news about my ut-71d and I decided to buy myself a new multimeter , Brimen BM867 . I chose this meter as it seems best for me and the work that I do, I have it for two months now and I like it. I have been looking for fault in the meter ut-71d and I concluded that measurement chip is faulty , I ordered a new one from china ... and the other day I managed to replace it . Original chip was ES51966P , but I put ES51966A because it was the only one I could find at the time. The device operates normally and I have not noticed any problems. I was pleasantly surprised when I found that there is nothing else defective and  everything works normally . The device deserves credit for surviving the shock of 2000V with "minor" damage . So now I have decided to keep ut-71d in the bag of tools and Brimen for the desk. I think the multimeter BM867 is more suitable for me, and as a personal opinion I think it is superior to ut- 71d overall. Regards, Leo.

[Wytnucls]

Kudos for fixing your UT-71D.
The Brymen 867 seems well built, with decent features, but it costs twice the price of your 71D.
I can tell you from experience, that the UT-71 meters are very stable and have very little drift over a one-year period. As far as I know, nobody has long term drift data for the Brymen yet.
It seems that the triple display on the 71 is slightly sharper than the 867. Can you confirm?
For bench work, the 71D is less bulky, comes with internal/external logging and a RS232 USB cable, at no extra cost.
Enjoy them both!

[TMM]

-The resistance measurement must not use the dynamic range of the ADC effectively because only has about 4000 counts of real resolution. This is undocumented and a major trap if you are unaware of it.
Not on mine, steading 40,000 count resolution on resistance. Measurement goes up to 400MOhm instead of 50MOhm on the Fluke.

How have you tested this? Try putting a low value pot in series with a high value resistor - e.g. 100ohm multiturn in series with 33K resistor. Then adjust the pot.

I find that the quantization levels of the ADC are 8-10 counts apart and while it shows readings in between this is only between the ADC is fluttering between two quantization levels and the meter is doing some averaging.

If you have a stable reading at say 33.050K, try adjusting the pot to get a stable reading at 33.051K. It doesn't happen. It will go from being stable at 33.050K, to fluttering between 33.050-33.060K, to being stable at 33.060K (or something similar to that, i just pulled those values out of the air  ).

I discovered this when i was measuring a bunch of resistors in order to match them and the exact same values kept coming up suspiciously often. It is also absolutely hopeless if you want to measure a resistor under 1ohm. Even after you delta out the leads the resolution bug gets you.

[/i]Few meters are perfect and the 187/189 is not one of them. Horrendous battery life and read the thread about leaking capacitors.

UT71 battery life is probably worse than a 187/189. 9mA current draw with the backlight off.

Don't get me wrong it is a reasonable meter for the price but i don't think it represents any better value than a Fluke 87V (even though they are in a completely different price bracket). Even if on paper they look very very comparable, when you start to use it you realize that extra money is well spent because it doesn't have all the quirks and stupid bugs that the Uni-T does.

edit: Oh and the other week i was measuring resistors using a wien bridge with the UT71D and noticed this in my results:

So now we are suppressing small negative voltage readings? I guess they were embarrassed about the noise performance of the ADC. Seems like every other month i notice another issue with this meter.

[Wytnucls]

I'll test the ADC quantization on the ohms range when I get home, but even if it is reduced on that range, does it really matter, since the guaranteed accuracy is far worse at 0.3%+8LSD, on most ranges? I can't think of an application where one would want or expect a high resolution on the ohms range.

From the Cyrustek ES51966 datasheet:
When oscillator is 4MHz, voltage/current can be counted up to 44,000, and resistance can be counted up to 42,000.

I don't usually compare the UT-71 to any Fluke meter, as the latter belongs to a far superior quality bracket. All I'm saying is that, for bench work, the Uni-T provides loads of reliable features, with few competitors at that price point.

[TMM]

I'll test the ADC quantization on the ohms range when I get home, but even if it is reduced on that range, does it really matter, since the guaranteed accuracy is far worse at 0.3%+8LSD, on most ranges? I can't think of an application where one would want or expect a high resolution on the ohms range.

When you need to match two or more resistors but the absolute value isn't important .

I needed two 6.8K resistors matched within 0.1% so i got out a tray of 1% metal films and found the resolution of the meter to be worse than that - about 0.14% @ 10counts resolution measuring a 6.8K resistor.

[Wytnucls]

The Cyrustek ES51966 is one of the best and most reliable Taiwanese DMM ADCs. So good in fact, that it was chosen by FLIR to equip their first high-end multimeter.
If you find some shortcomings with it, FLIR or Cyrustek would be delighted to hear from you, I'm sure.

When I want to match or measure resistors to a high precision, I tend to use an LCR meter.

[aurelleostean]

The Brymen 867 seems well built, with decent features, but it costs twice the price of your 71D.
It seems that the triple display on the 71 is slightly sharper than the 867. Can you confirm?
For bench work, the 71D is less bulky, comes with internal/external logging and a RS232 USB cable, at no extra cost.
Enjoy them both!

Salut, and thank you!

I am sorry to disagree with you but the ut71d is 153 Euro and bm867 129 Euro plus taxes, you can check on tme.eu .As I see it the screen of the bm867 has more contrast, better viewing angles, stronger backlight, and not the other way around. The ut71d has a sharper display if you have the meter close to you face, but I prefer the display of the bm867 as it is more suitable to my needs. I think the ut71d was build for people that have more then 2 meters in height or for those that put the meter on the floor to read the display, in fact not even on the floor but on a chair at the same height as your bottom. On the bm867 the tilting bail is longer and you can actually read the meter display sitting on the chair and not in your feet, and in my opinion the tilting bail of bm867 is almost perfect. Yes the ut71d comes with a usb cable, that is useful to record data on pc and so on... but I do not use it, and the fact that you do not have a cover for the big, pointy corner hole the usb interface leaves behind when you are not using it, to me it is pretty annoying. Hope this helps! Regards, Leo.

This is a super fake picture of the ut71d:
http://images.batronix.com/products/multimeter/UNI-T/UT71D-oblique-l.jpg

This is what you see most of the time:
http://i1.ytimg.com/vi/ZRZCtl0x4Rk/hqdefault.jpg
http://i.ytimg.com/vi/vk7S-cJs4KM/0.jpg
http://img202.imageshack.us/img202/4346/28577144.jpg

This is how a photoshoped bm867 display looks:
http://www.netes.com.tr/upload_x/genel/BM-867-33B3A43A457FE9186416E985FC41B2BE.jpg

This is how I see it:
http://www.google.ro/imgres?start=130&espvd=210&es_sm=122&biw=1280&bih=628&tbm=isch&tbnid=GA7qmkQi_BxLqM%3A&imgrefurl=http%3A%2F%2Fwww.eevblog.com%2Fforum%2Ftestgear%2Fbrymen-bm869-review-by-the-eye-of-the-industrial-electrician%2F&docid=9Hhvx4VfmH2HnM&imgurl=http%3A%2F%2Fwww.eevblog.com%2Fforum%2Ftestgear%2Fbrymen-bm869-review-by-the-eye-of-the-industrial-electrician%2F%253Faction%253Ddlattach%253Battach%253D18069&w=900&h=675&ei=qUX-Uv_QGqbmywPgtoCgDA&zoom=1&ved=0CF8QhBwwHjhk&iact=rc&dur=1173&page=7&ndsp=24



 

[Lightages]

Wow, such price discrepancies here. The UT71D is readily available on ebay for around 120 euro or $160USD shipped to your door. Using TME as a price guide is a bit useless as they have some of the worst prices for Uni-T and some of the best prices for Brymen. But this still does point out that the BM867 is nowhere near twice the price of the UT71D. The only reason to buy a UT71D over a BM867 is to get temperature and internal logging. I would rather buy a BM867. For everyday use it far out performs the UT71D in speed, build strength and safety. Yes, the UT71D comes with a PC cable and software which costs $50USD more from Brymen.

If I were looking for a bench meter that does almost everything and I was never going to use it for high energy and didn't care about the slooooww continuity test then I would consider the UT71D better buy.

I am a bit biased against Uni-T because my UT71E came out of spec with readings more like 0.4% accurate rather than 0.05%.

[Wytnucls]

The 71D can be had for 114 Euros delivered to your door in France.
http://www.ebay.fr/itm/New-UNI-T-UT71D-Intelligent-Digital-Multimeter-/121183663433?pt=LH_DefaultDomain_0&hash=item1c371bf549

Well, obviously, the 71D is not for you. I think it is the most useful meter one can get for low power bench work, at that price point. But I don't expect everybody to agree with me. I don't have a problem with the bale or the screen and there is a work-around for a fast continuity. There is nothing wrong with the BM867, if you can put up with the reduced 1 kHz AC bandwidth (100kHz on the UT71) and especially if you can get it with the logging contraption, for a similar price, but I doubt it.
The Brymen with the logging cable, VAT and postage costs about 210 Euros. In my book, that's nearly double the price of the 71D.

[Lightages]

Actually, I would buy a UT71D if I did not have a logging multimeter and had another good one for safety. It is a good buy if its limitations are taken into account.

It is also hard to pin down the end prices for things when we are talking to people all over the world.

[peter.mitchell]

TL; DR, you get approximately what you pay for; usually less but sometimes a little more.
You pay $50 for a meter, you get less than or equal to $55 worth of meter.
You pay $400 for a meter, you get less than or equal to $440 worth of meter.

There is almost never an occasion where you will spend $50 for a new meter and get $400 worth of meter. That isn't how selling things works.