[volt-nuts] HP3458A _really_ long term stability

[Andreas Jahn]

>>The result:
>> Internal 40K resistor:   -11.66ppm
>> Internal 7V Voltage ref: -28.96ppm
>>
>>That's not too shabby over 15 years...
> 
> Update:
> 
> Greg Burnett and I have been chatting offline, and it transpires,
> based on the serial number of 2823A00556, that it is more like 22
> years.
> 
> Appearantly this instrument was never calibrated after it left
> the factory in late 1988 or early 1989.

Hello Paul,

If the last cal was really before 1.1.1990 remember that the
official volt has been redefined at 1.1.1990 by +8.06 ppm.
So all readings which were made before have to be corrected by -8.06ppm.

With best regards

Andreas