[volt-nuts] Keithley 6517A electrometer fault

[John Devereux]

Hi, hope this is not off topic - well it does measure volts...

I just received a 6517A electrometer but it appears to have a fault.

On volts, with shorted input, the reading usually drifts rapidly
upwards. For example 10mV in 10 seconds on the 2V range.

It is usually OK (stable to 10uV) at power-up, but the fault can be
provoked by tapping it lightly with e.g. a finger. Then it runs
away.

I can hear a faint noise, very like a relay switching when the unit is
tilted. Nothing obviously loose or rattling inside...

Has anyone seen this? Could a reed relay fail like that?


-- 

John Devereux