USE OF PRECISE DIGITAL VOLTMETERS FOR IMPEDANCE MEASUREMENTS
Damir Ilić, Ivan Leniček
Abstract:
The traceability chain of the Primary Electromagnetic Laboratory (PEL) is presented, and the place of the resistance standard of 100 MΩ is analysed in details, as well as its construction and characteristics. Its one hundred 1-MΩ elements in parallel connection forms the 10-kΩ value, and can be easily compared to the reference 10 kΩ standard of PEL; in that way its long-term drift was found to be ≈ 0,067 ppm/day (ppm means parts per million). Furthermore, the method of comparison of 100 MΩ resistance standard by means of 100 pF capacitance standard and high-resolution digital voltmeters (DVs) is analysed, where DVs measure ac voltage of frequency close to 16 Hz in dcv range, and the mean value of one-third cycle is measured. It was found that the voltage ratio could be stable within the limits of 0,1 ppm when the additional frequency stabilization of the ac calibrator is used.
XIII IMEKO TC4 International Symposium on Measurements for Research and Industrial Applications (together with IXth International Workshop on ADC Modeling and Testing, IWADC)
