HP-3468A, Display Voltage VDC

[Uli]

(04-24-2021 02:00 AM)BobVA Wrote:  This is normal. What you're seeing is noise induced in the probe leads from (mostly) nearby AC power lines. The sample time of the HP3468A is fast enough to snapshot this (lower sample times average it out to near zero) so you see random values.

Dave Jones did a deep dive on this topic:

Thank you for this idea and for the video link that I did not know before. That might be the reason. But ... there is always a but ... my HP-3468A shows +2,86 VDC without any measuring device. Without measuring cables plugged in. And I have carried the HP-3468A into my garden to test it outside. Same result. Now I have to read the manual to learn how to reduce the sample rate, to see what will happen.