Resolution limits in radiation temperature measurements using unfiltered photodiodes as detectors

Abstract

This paper attempts to determine the practical and theoretical resolution limits of black-body (BB) radiation temperature measurements. The calculations were restricted to unfiltered Si, Ge and InSb photodiodes and to the 100 °C to 1500 °C temperature range. A measurement geometry determined by the fixed-point BB construction was used with a view angle of 3° and an observed area of 1 mm2. Current best technology for detector long-term noise performance was assumed. The calculations show that the best resolutions are 15 mK to 40 mK for InSb, 6 mK to 15 mK for Ge and 2 mK to 8 mK for Si fullband pyrometers in the temperature ranges 100 °C to 280 °C, 280 °C to 500 °C and 500 °C to 1100 °C, respectively. These results require very good temperature stabilization (better than 0,01 K) of the detectors.