Study of the long term performance on the calibration data of the coaxial thermistor mounts up to 18 GHzud

摘要

National Physical Laboratory (NPL) India is the premier research and development center and the National Metrology Institute (NMI), which provides traceability in measurements by calibration throughout the country. Radiofrequency (RF) power is one of the most important quantities in RF metrology. The calibration of the reference standard thermistor mount and the unknown thermistor mounts in the frequency range of 50 MHz to 18 GHz has been carried out using coaxial microcalorimeter and direct comparison technique respectively. The long term stability performance study carried out on the reference standard thermistor mount and the unknown thermistor mounts is reviewed in this paper. The results show that the maximum deviation in the calibration results of the reference standard thermistor mount and the three unknown thermistor mounts over the period of seventeen years is within +/- 0.4% and +/- 1.5% respectively from 50 MHz to 18 GHz.