thanks for checking with your 2001, that´s very interesting. I have not used by myself such high class multimeters, so I have no comparison. Yes I know about the offset of TRMS-DC-converters, but I was hoping that they use a kind of auto-offset trim from time to time in such an instrument. But I find the postings of EVS and Macbeth´s DM3058 also very interesting.
I have seen this on cheap multimeters (e.g. UNI-T) at times, even for DC; they just suppress low readings and make them artificially zero. This looks good, but it's a fake. For TRMS AC it is legitimate though, as the range below at least 1% of the range is unusable anyway. For the Keithley 2001, ACI rms measurement is even only specified for 10-100% of the range.
My Picotest M3500A does the same thing, it shows zero below 1% of the AC range (and it’s a quite good meter). The A-brands like Keithley 2015 THD, Keithley 2001, Fluke 8840A and 8842A do not.
REL-ing is of corse no option (was off on EVS´s pictures). They seem to have even a zero offset (what I would not expect).
I thought someone else (not you) mentioned this, so I just wanted to make it clear that this is a big no-no.
What bothers me most, is the high input resistance of 3.3 Ohm @ 200 mA. I selected this instrument for its advertised 1 Ohm shunt.
Anyway, I just returned it to the dealer for full refundimg. The search for a good multimeters goes on....
Current measurement is always a problematic issue. With high shunt resistors, the burden voltage is high too and introduces systematic measurement errors, plus the self-heating of the shunt causes additional errors at higher currents. With low shunt resistors, we cannot get high accuracy right from the start, because of the low voltage drop. This is why serious bench multimeters the burden voltage will either not be low or they have a miserable accuracy as was common a few decades ago, where many bench meters only had a single shunt resistor and only very few current measurement ranges, only one of them with decent accuracy.
On the Keithley 2001 I can measure ~2.4 ohms in the 200mA range.