Hello everybody.
I finished a reference resistance box a while ago in the same way as Dr. Frank have described his own reference in this forum. I used the Vishay metal foil series resistor VHP101 (Y407810K0000V9L, Digi-Key Part Number 804-1059-ND) which is 10 kΩ, 0.005% and a TC of 2ppm.
My 3458A is from 2013 and last calibration was in 2015. The 3458A has been on 24/7 for the last 2,5 years, works well. I’ve been monitoring it as per Service Note 18 and A/D drift seems to be low. I cannot say anything about the 3458A’s internal 10 V reference as I have no external reference of quality.
I’ve measured the reference resistance at ambient temp. 23 ⁰C ± 2 ⁰C (same temp in the resistor box) and Rh 47%. I used the MATH STAT function and got the mean value (and deviation) of 16 readings each time and there is a total of 100 samples of that kind. The samples are in the range 10.000 295 to 10.000 310 kΩ; the mean value is 10.000 304 kΩ. To me this seems nice and repeatable.
However, my question is, can the readings be trusted when using a 3458A “out of cal” for resistance measurement and is the result good enough to make it a reference resistance? Or are the measurements just rubbish and can be discarded? Any views on this are appreciated.
Franklin