Miall, J (2001) Calibration history of waveguide thermistor power standards in the UK. In: BEMC 2001- 10th British Electromagnetic Measurement Conference, 6-8 November 2001, Harrogate, UK.

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Abstract

The efficiencies of, widely used, commercial waveguide thermistor sensors have been measured periodically from 1981 to the present day to provide the U.K.'s national standard for waveguide power. Prior to this date in-house tuned bolometer sensors were used for this purpose. The effective efficiency of the thermistor sensor is measured using waterbath microcalorimeters in waveguide sizes IEC R-100 (WG16), R-140 (WG18), R-220 (WG20), R-320 (WG22) covering the frequency range 8.2 GHz to 40 GHz and have typical uncertainties of ±0.6% to ±0.8% (at 95% confidence interval).
The raw data from these measurements has been re-analysed to give the long-term stability of this type of power sensor at a range of frequencies across each waveguide band and the repeatability of our waterbath microcalorimeter systems in the three laboratories that they have been situated in during this period. The data shows the thermistor sensors have good long-term stability with generally good consistency between the three laboratories.

Item Type:	Conference or Workshop Item (UNSPECIFIED)
Subjects:	Electromagnetics Electromagnetics > Electrical Measurement
Last Modified:	02 Feb 2018 13:17
URI:	http://eprintspublications.npl.co.uk/id/eprint/2214

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