[volt-nuts] Solartron 7081 Calibration Update

[J. L. Trantham]

Having shipped my 7081 to AMETEK in Oak Ridge, TN, on Thursday September 29,
it returned Friday November 11, having completed it's trip to England and
back.  It survived the trip without incident, left via FedEx and returned
via UPS.

The 'AS FOUND' was within spec except for the 1000 Kohm range (119% of Tol)
and the 100V and 1000V DC ranges (223% and 113% of Tol respectively).
Battery B1 was replaced (B401 had been replaced recently) along with three 1
K resistors and the front connector which was a problem to begin with.
Also, the front panel where the connector and CAL switch are located was
either replaced or redone.  It was a bit scratched up when it left but is
pristine now.  The 'AS LEFT' errors were typically single digit % of TOL
though the 1 V AC @ 100 kHz was 54% of Tol.

When it returned, I removed the 'CAL Sticker' over the CAL switch, put it in
the CAL position and downloaded the CAL DUMP.  The numbers are different
from what I found before I sent it for calibration, as expected, but the
Zener Current Token Value was the same at 081.  I suspect that this means
that the reference is now 'stable'.  The 10.000000 V 'REFERENCE' was found
at 9.999856 V (72% of TOL) and was left at 9.999993 V (16% of TOL).

I used the 7081 to measure my 'standards' then used that data to calibrate
my 3458A.  I then archived the DS1220Y 'CALRAM' data from the 3458A.  Next
on the agenda will be sending the 3458A to Agilent for calibration.
Somewhere in there, I am going to have to learn to 'read' the data from the
3458A via HPIB.

So far the repair and calibration were free.  I haven't seen a charge on the
AmExp card yet.  The quoted price was $900 for calibration and alignment.
Battery replacement, repairs, and connector will be extra, not to mention
the shipping.

Joe