[volt-nuts] 7081 AC problem

[David C. Partridge]

I've now got the DC ranges calibrated using the other 7081 as a yardstick.

I've now moved on the the AC ranges and am having a problem 

calibrate,vac=0.1,high=0.100019
OK
Calibration incomplete
  0.100021
  :
  :
  0.100031
  :
  :
  0.100041
  :
  :
  :
  0.100302 and still climbing.

The other meter is reading a rock steady 0.100019 Vrms

Interestingly if I switch to the AC+DC volts range it reads a stable 0.099868V (a bit low).

Thanks
David Partridge