Uni-Trend UT71C - Page 1
Forum section: electronics / testgear

author: Medo
author_rank: Regular Contributor
timestamp: April 03, 2013, 04:57:45 am
content: As I was going through some old pictures, I found ones that I took of UT71C insides. It has been almost two years since, but I figure that current models are probably similar (if not identical) in build.It came in nice fabric carry bag and package included leads (pretty sharp, no rating), k-type probe (very flimsy), some clips (nothing too fancy), USB cable, and some assorted junk (cd, manual...). 9V battery was also included, and I will leave you to guess which type it was...Device is a bit on bigger side and twist test shows that nobody cared too much about structural integrity. Range switch and display are passable. Dave will be sad to hear that there is no transistor tester.Function-wise there are no major distinguishing features, but 4-20 mA current loop reading is at least worth mentioning. Display update speed is as fast as snail underground, continuity test beeps only when you hold probes for a week, and working white LED is just a dream.At every range change it will beep at you but that is configurable. Just notice that, if you turn off the sound for range switch, there is no beep for continuity test either!First thing I noticed after opening case is that case already had some stress-induced notches at top next to screw hole and extending a bit into it. After first fall this will probably snap completely.Whoever wrote that this is CAT IV/600V device was probably high on Peking smoke. Input protection is almost non-existent (one PTC + power resistor) and both fuses are glass. Isolation slots are nowhere to be found but at least case has an U-channel but nothing too deep.Input connectors are cheap split ones but they actually felt ok. However, I have no doubt that they will get worse with time. Solder joints are of usual Chinese quality and let's not forget that it is a sin to clean a board.PS: I probably forgot bunch of stuff because lot of time has passed, but this is gist of it.

author: Medo
author_rank: Regular Contributor
timestamp: April 03, 2013, 04:59:24 am
content: Additional images...

author: Lightages
author_rank: Unknown
timestamp: April 03, 2013, 05:28:48 am
content: Thanks for another opinion on the UT71X series. People seem to have varying ideas as to whether these are good or bad.

author: retiredcaps
author_rank: Super Contributor
timestamp: April 03, 2013, 06:13:21 am
content: At least for the 9V battery snap, they are using the hard plastic shell instead of the usual soft plastic. I prefer the hard plastic one as I think it provides better protection for the solder joints on the 9V terminal snap when you eventually change batteries.Some of my multimeters pathetically only have 100 hours for run time.

author: Wytnucls
author_rank: Super Contributor
timestamp: April 03, 2013, 06:38:00 am
content: You did forget a bunch of stuff:40,000 countInternal data logging meter 100 data points (fast RS232 delayed transfer to computer available)Data recall functionIncludes USB cable with software for data logging (selectable interval)True RMS AC or AC+DC meterFast display update speed on 4,000 count modeAural input warning on Amp jacksmV (2.5Gohm) and uA rangesProbably the best display of any meter with 2 step backlight, apart from Agilent's AMOLED screenMin/Max/Peak holdSelectable Min/Max for device tolerance sortingTriple data display2 types of bar graphs availableConfigurable sleep mode3 year warranty if bought from accredited reseller in Hong Kong

author: Medo
author_rank: Regular Contributor
timestamp: April 03, 2013, 06:42:13 am
content: Those are all things that are covered in its manual.I tried to give more of an critical "feelings" overview.

author: Wytnucls
author_rank: Super Contributor
timestamp: April 03, 2013, 07:20:25 am
content: 'Function-wise there are no major distinguishing features'I just listed the distinguishing features that you missed and I wouldn't call them minor either.

author: Medo
author_rank: Regular Contributor
timestamp: April 04, 2013, 02:47:53 am
content: Ok, I accept correction and admit that I used words carelessly.PS: Here are reasons why I personally thought that it is worth my money:0.025% base DC accuracynice accuracy on current range4-20 mA current loop measurement400 MHz frequency measurementRS-232 connection (although software is awful)On other hand this is not a quality multimeter. Input protection is really lacking and CAT IV rating is exaggerated at best. I don't think it will age well, nor that it is trustable for any longer period of time. Of course, this is purely my personal opinion.As long as you know what you are getting for your money, this multimeter might be a good choice. Frankly, considering the price, it might be even an excellent one.In any case, images are uploaded and everyone can draw their own conclusions.

author: Wytnucls
author_rank: Super Contributor
timestamp: April 05, 2013, 10:38:01 am
content: This is not a scientific test, but is more relevant to the quality of the meters than esoteric statements.I can report that there is virtually no drift on the DC Volt range (2-14V) between my UT-71B and 71D over a 4 month period (1 count at most). My 61E, which I had adjusted to match the 71s, has drifted quite a bit over the same period, in relation to the 71s (between 2 and 7 counts).The 71D has its original calibration. The 71B was calibrated and adjusted 4 months ago by UNI-T, at the factory.(Voltages provided by linear power supply, with no reading fluctuations on the meters of more than 1 count)The 'lab' is air-conditioned at a constant temp of 23C.I found the logging software to be adequate and useful, especially when the two meters are registering voltages and currents in real time.

author: pedderson
author_rank: Newbie
timestamp: September 26, 2013, 12:22:31 am
content: Hi,I just bought a UNI-T UT71C and since I read everywhere that there are just glass fuses in this multimeter I ordered some extra ceramic fuses to replace the glass ones. When I opened the multimeter to replace the fuses I noticed that there were already some ceramic fuses in there. I don't know if this is standard version of the UT71C or a special version of the it for the shop/germany/whatever, but the layout of the board also seems to be a little bit different from the pictures I saw everywhere else (including the previous post). I hope they could fix some of the problems I just read about in this forum (for example safety specs).

author: Wytnucls
author_rank: Super Contributor
timestamp: September 26, 2013, 05:27:17 am
content: The board has been revised to accommodate HRC fuses. They moved a few things around. At first glance, the shunt is smaller, there is an extra precision pot installed and a high voltage gap routed in the PCB.Possibly just a special version for importers in Europe (Conrad?), to comply with the latest safety requirements, or a revised PCB for the whole range.Still, just one PTC and no spark gap or MOV on the board yet.

author: em132
author_rank: Contributor
timestamp: September 26, 2013, 05:45:13 pm
content: Quote from: Wytnucls on September 26, 2013, 05:27:17 amBut with an "SG1" spot just ready and willing to accept a nice, juicyCG21000L.As-is, it's still amassiveimprovement on the fuse front.

author: Wytnucls
author_rank: Super Contributor
timestamp: September 26, 2013, 06:00:50 pm
content: You mean like this?