The BIPM has characterized seventeen Fluke 732B instruments for temperature and pressure effects. These Zener standards are offered to national metrology institutes for use as travelling standards in our programme of bilateral comparisons of voltage standards.
It was found that the influence of ambient pressure on the output voltages of a Zener is reproducible, so that it can largely be elimated by applying corrections; such corrections reduce the measured differences and the corresponding uncertainties. Overall, the relative voltage changes due to pressure are very small (less than 5 parts in 107 for the greatest pressure changes normally encountered) but the effect can be important to national metrology institutes and users of Josephson voltage standards.
Fourteen of the seventeen standards studied were found to have statistically significant temperature coefficients (TCs) at 1.018 V and ten were found to have statistically significant TCs at 10 V. Measuring TCs and applying corrections for temperature dependence can reduce errors in calibrating and comparing these standards.
Summary
The BIPM has characterized seventeen Fluke 732B instruments for temperature and pressure effects. These Zener standards are offered to national metrology institutes for use as travelling standards in our programme of bilateral comparisons of voltage standards.
