Hello Alexander,
I think, everything is fine with your instrument.
At first, your pictures are not very good, display nearly unreadable, maybe you finally could remove that protection foil...
2nd, be aware, that both the current jacks have a segmented plug detector inside.. so that the instrument can detect, if and where's a plug inserted, and to beep if the jack used does not fit the selected range, and also to do some internal range switching.
If you don't plug anything in these jacks, that is a non-defined state. Maybe there's a small current flowing from the detection circuit.
Anyhow I also see some counts offset in that state.. so forget about that.
3rd, for the 50µA range at least, maybe you have a look in the manual, page 16, footnote 4, about offsets due to x10 amplification, that might also apply to other ranges.
Simply use REL to zero these effects.
4th, whenever you connect two cables, especially holding them with your warm fingers, you'll create a thermo - couple, which not only creates a thermo voltage, but also creates a current (Peltier element / Seebeck effect).
That also depends on the quality of your cables, and the finish of the tips.
You're using these cheap clamps, so that's no wonder. That should not happen (or give a small effect only) with the gold plated brymen tips.
Remember, that you're down to 1nA in these ranges, and 1µA also can easily be generated by this effect.
Try different cables, and if you don't touch that junction with your fingers, probably these currents vanish when it adopts room temperature again.
Frank
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Thanks you for the reply. I could understand it for 50 uA range and I mentioned it in my original post. But in 500 mA range also? And why only DC mode?
This offset current is always there. Regadless If I connect probes or not. I tested with many probes. With golden ones, even with a thick wire soldered directly in banana plugs.
And the most important is that the meter measures high in relation the the other meters I own. How much higher? 100 uA. Exactly the offset I see. If I rel the offset, it measures exactly like the others.
What the rest of you see if you sort COM and 500 mA input?
I am just trying to figure it out. To understand it.
Alexander.