Microwave power sensor calibration using direct comparison technique with different adaptors

The effects of different adaptors on microwave power sensor calibration using direct comparison transfer technique have been investigated in this paper. The calibrations are implemented with a mathematical model developed recently. To verify its accuracy in calculating the calibration factor, a comparison is carried out between the mathematical model developed and those reported by other researchers. The comparison indicates that the model is suitable for microwave power sensor calibrations. For its implementations, a 0 dB adaptor, 10 dB, 20 dB and 30 dB attenuators are used to evaluate the effects from different adaptors. Preliminary results show that when the attenuation of an adaptor increases, the expanded uncertainty of the calibration factor increases correspondingly, following the Guide to the Expression of Uncertainty in Measurement (GUM). Moreover, the results of GUM are also verified with the Monte Carlo Method.