Products > Test Equipment
UNI-T UT61E Multimeter teardown photos.
RedSky:
Anyone had trouble with UNI-T 61E and getting accurate measurements on DC-DC converters?
Mine simply has no hope of accurately measuring the DC input to a synchronous DC converter running @ 64kHz, which runs in the 12-100V region input to adjustable output DC.
It's off by several volts DC no matter what the input or output, as much as 10 volts or more in worst case scenario. Even some cheap $10 meters I have do a much better job, as well as a much more budget UNI-T 33A.
The input is from a solar panel so it's fairly stable DC supply and no it's not fluctuating sun causing it. My UNI-T 70D shows accurate voltage readings, and the DC Converters own meter also shows accurate voltage, which is a micro using internal ADC's measuring off a resistor divider (averaged readings)
The input to the DC converter has little AC voltage present <100mV on the signal, and a number of low ESR capacitors ceramic and bulk low ESR electrolytics on the input.
My UNI-T61E is super accurate when tested with a DC voltage reference and on ohms range when tested with 0.1% ohm resistors.
Anyone else seen issues like this?
Apologies if this has already been mentioned, I read most of this (huge) thread.
dinoboy:
This thread never gets old i guess... :popcorn:
I couldn't find a RL photo of the European version of the multimeter, so here we are:
As you can see, the ratings are very different from the International version (feel free to compare with your own unit)! Also inside, the PCB and electronics are very different: more components and higher quality more expensive components, fuses, etc. Some trace sections of the PCB are similar but about 40% is different, easily seen from the traces and populated components. Yeah sure, mostly for better input protection and for really matching the ratings printed on the front. Those lowered ratings were then certified by the top highest German Authorities both GS and TÜV, which are commonplace language items in geman households.
So for the International version UNI-T designers simplified the schematics, reduced the number of components, populated cheaper components to cut the costs and the retail price, and at the same time they raised the labeled ratings oic
:-DD
My neighbor got his European version from a Dutch retailer but the instruction manual was in geman, here are the source PDFs for your reference:
* UT61E Instruction Manual Geman Reichelt
* UT61E Instruction Manual Geman Pollin
Needless to say, typical pricing for the European version is expensive at 85EUR (2017), whereas the International version can be bought at 45EUR (ebay). The current packaging list is also slightly different: the UT61E nowadays comes with a 'bracketed' holder for the transistor measurement (you can see part of the bracket in the above photo) and with a USB data cable instead of the serial data cable. I didn't have good experience with the USB data cable before, though, as described possibly on another forum. Hence I continue employing the serial data cable and, if needed (see my previous post), a Serial-to-USB adapter based on the FTDI chipset series.
If people have/use the UNI-T USB data cable and are wondering, just do a 24.0h logging test (of voltage or current) and check if your Excel file is complete:
24h * 3600s/h * 2Hz = 172800 data points
Your Excel file should have 172800+ rows. Does it? Well, mine didn't when i used the UNI-T USB data cable. It did when i used the UNI-T serial data cable. There you have it. I don't trust the UNI-T USB data cable anymore.
Cheers, going on summer vacation now, bye!
Fungus:
Where can people buy them?
dinoboy:
People can buy the European versions of UNI-T products from the German importer Reichelt, look out for the "TÜV GS"-logo printed right below the LCD screen:
https://www.reichelt.de/UNI-TREND/Herstellersuche/103/index.html?ACTION=103&LA=103&MANUFACTURER=UNI-TREND
The EU version is also sold by committed chinese :palm: vendors on Alibaba and Aliexpress but that's none of my business :o
Fungus:
OK. :-+
PS: I didn't know Uni-T made cheapo desktop meters. They're cute - a bit like those old Fluke 8050As! :D
(but autoranging)
Edit: And weirdly enough, much cheaper there than on eBay. :-//
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