[volt-nuts] hp3457a low voltage range behavior
juris.l at gmail.com
Tue Sep 3 07:55:46 EDT 2013
Hi group !
After long waiting for cheap listing with possibility to european delivery,
at last win 200$ ebay "parts" hp3457a meter.
Now only now need to find someone local with better equipment to check
Meter works fine, but I'm not sure how meter must behave in low voltage
If I short leads it show ~1uV, thats Ok.
But if leads not connected then voltage slowly creep up from zero and after
about 5 min
grow to +3v and meter start to click relays trying to autorange.
So look like somewhere inside is ~15GOhm leak to + voltage, i try to clean
board with isopropyl , but no big changes.
So is it normal (I doubt...) , because 10GOhm input impedance, or something
is wrong and need to repair ?
Any input will be appreciated!
More information about the volt-nuts