[volt-nuts] 732A and 3458A stability

[Randy Evans]

I ran a stability test on my  "new" 732A and 3458A units.  I had both
connected together (using copper wire leads) and I randomly ran
measurements of the 3458A reading of the 732A 10 VDC output.  I did an ACAL
DCV before each reading and used NPLC of 100 and 8 digit readings , and
recorded the room temp, 3458A internal temp , and the MIN/MAX/MEAN/STDDEV
of the 3458A readings, and the thermistor value of the 732A.

The room temp varied from 22.1 to 27.9 C over the several days of
 measurements.  The 3458A internal temp was, on average, 13.7 C higher than
the room temp.  The end result was a temperature sensitivity of 1.15uV per
degree C of the 3458A internal temp, or .115ppm/C.  I am assuming the 732A
is relatively stable over the changing temperature range (the thermistor
varied from 3666.6 to 3670.7 ohms) and attribute most of the variance to
the 3458A.

The absolute value of the readings are around 10.000058 VDC but neither
unit is calibrated.  I assume they can be calibrated but I wanted to make
sure they are stable first.

Do these numbers look reasonable and do they indicate any issues with the
units?

Thanks,

Randy Evans