This is really helpful Henrik, thank you.

I think I know what’s happening on your meter, and if it’s happening on yours I suspect it might happen on some others.

A while ago I found a hardware bug on the meter that I detailed here. The jist of it is that when the current source is operating with very low overhead, it can enter a lockup mode where it reads about 30% higher than it should. I rejiggered the firmware to knock the meter out of lockup in the right conditions, but apparently on some meters the firmware kick is not strong enough to knock the current source out of lockup.

I think that since your meter seems to have the lockup issue, that’s what’s precipitating the range switching as well. Hooking up a 10k resistor to the 10k range might lock up and read 13k, which causes the range to step up, which changes the current source output from 100uA to 100nA, which alleviates the lockup and causes the meter to read 10k, which causes a range step down, etc.

Sorry for the run-on sentence. Thinking as I write. I’ll look in to the lockup bug again and see if there’s something I missed in the firmware fix. One idea to try in the meantime is to remove the batteries, clean the circuit board with rubbing alcohol, and try again. You’re international, so a return would take a long time, I think the fastest way to resolve the issue would be to wait for the next firmware version. If that doesn’t work then I’ll happily replace the meter.

Is it otherwise working for you? Best
~James