LCR meter opinion

[marcus h]

I've got a Uni-T UT622A on the way.

622A 

100Hz, 120Hz, 1KHz, 10KHz    99999 Count
0.00pF~99.999mF
0.00μH~99.999H
ESR 0.0000Ω~999.99Ω

Uni-T do not specify accuracy on the various ranges  It could be dreadful at 1pF and 1μH. 

There are big differences in maximum ranges.  For example the UT-622 series max out at 99.999H while the DE-5000 can go all the way to 2.0KH.   That is a very big inductor.

If 100kHz is important, the ~$300 UT-622E adds a 100kHz test freq and DC resistance with .01milliOhm resolution.

This is a late reply to this older topic but given the scarcity of information on the UNI-T UT622 LCR-meter series in this forum I think that a reply to this old posting is warranted.

Andrew cites the display range for inductance as "0.00μH~99.999H" which I think comes from the official datasheet -- which is still available (see link below).

However, the user manual (page 41, also see link below) gives a much more believable range: "0.001uH - 9999.9H"
That would mean 10KH.

Why is that "much more believable"?
Because it has a) a more realistic looking lower ceiling of "0.001" instead of "0.00" uH
and b) the other display ranges look less like a cut & paste job in the manual (resistance only 10 MegOhms?).
Also consider, this is a 99,999 and not a 9,999 count device. Higher/Lower ceilings are expected (even if they aren't necessarily more accurate).
Finally, datasheets are usually getting produced much earlier than the manuals.
Therefore I conclude -- albeit without final proof -- that the manual has the correct values.

I wonder how many customers they lost thanks to the (still!) faulty datasheet?

And indeed: UNI-T doesn't provide an accuracy table. Neither in the datasheet, nor the manual or on their website.

What they offer, though, is a rather large section in the manual how they calculate the accuracy (pages 42 - 44).
The accuracy formula for L/C/R/Z/X/DCR measurements contains lots of stuff but the gist of it seems to be that you have to try to get the best parameters under the circumstance.
This accuracy will never get better than 0.1 % and it will likely get worse (= higher %), depending on the parameters (voltage level, speed) and more (impedance, temperature...).
It looks a bit like they tell us "use friendly parameters and hope for the best!"

On a final note, the UT622-series consists of three models:
622A: max. 10 kHz, no DSR-measurement, alligator clip test leads with rubber plugs
622C: max. 100 kHz, no DSR-measurement, four-terminal kelvin test leads
622E: same as 622C but with DSR-measurement
Everything else should be the same, including accuracy, speed etc.

So if you want 100 kHz but don't need DSR you could get the 622C which is much cheaper than the 622E.

Both the datasheet and the manual can be downloaded here:
https://instruments.uni-trend.com/EU-EN/search?scode=all&name=ut622

Product page (links to manual & datasheet don't work for me):
https://instruments.uni-trend.com/EU-EN/lcrmeters/ut622.html

HTH

[Andrew_Debbie]

I've had my UT-622A for over a year now.   
It came with a multi-page calibration document and (sigh) clip leads.

The meter works. It meets my needs. 

For small parts, I stick the leads in the socket for the Kelvin lead set. For big parts, the error introduced by the clip leads is usually a don't care.

The kelvin leads are available seperately for about $60 US. If you think you might want them, get the 622C which is about the same total cost but has 100kHz.



There is also a less expensive 20,000 count Uni-T UT612. It comes with a 4-wire tweezers.    The 612 is from their "meter" divison.   The 622 is from the instruments side.


622 series:
https://instruments.uni-trend.com/EU-EN/lcrmeters/ut622.html

612:
https://meters.uni-trend.com/product/ut612/

[Andrew_Debbie]

Not a review, but here are some photos:

Unboxing.   Note the multi-page test report.


Initial power-on user interface is not in english.   It was not hard to change.



470µF Nichicon UPW at 100Hz


Amveco / Talema 70000K series

[ogden]

Not a review, but here are some photos:

Thank you for sharing. Nice calculator indeed!