Here we go,
I have compiled the basic accuracy verification, (comma used for the decimal point.)
All ranges are very well inside the (barn door wide) specification, mostly a factor of 10 more accurate than specified.
The linearity of the A/D_1 is quite good, but it shows a very pronounced Rollover Error of about
3 6 digits. I've expressed these both characteristics commonly by the overall DNL, Differential Non Linearity, over the nominal +/- 5.0000 V range, which computes to 2 digits, which is quite OK.
Only the 500k, 5M and 50M Ohm ranges show a strange behavior.
500k and 5M might be quite jumpy all of a sudden, or rock stable the other instance, always with the same physical setup.
The accuracy changes from one day to the other, or from one power-on to the other.
Latter goes also for the 50M range, which integrates much slower; 2 days ago it was out of specification, as it was today morning, but in the afternoon, it was inside spec, but varying from one power-on to the other.
Seems to me, that some internal interference occurs, as if the firmware creates spurious interrupts which affect the readings.
I monitored these different behaviors and will report elsewhere.
Otherwise, that instrument seems to be of very good quality, but not so well specified or qualified by UEI.
I think, that it performs much better, in the same league like other, more expensive DMMs.
Frank