Study on the Infrared Lens-Free Irradiation Thermometer Based on InGaAs Detector at NIM

摘要

A lens-free irradiation thermometer (LF-IRRT) designed for laboratory applications, with center wavelength based on the InGaAs detector, and a temperature range from to , has been developed at NIM of China. The thermometer has no imaging optics for collecting the radiation, for which a major benefit is improved stability compared to other radiation thermometers. This paper introduces the measurement principle, the structure of the LF-IRRT, the multiple-point calibration method, and the stability and expanded uncertainty of the thermometer. The stability of the LF-IRRT is better than at temperatures from to over a period of 1 month. The expanded uncertainty is less than for temperatures between and . The size-of-source effect of the LF-IRRT is 0.6 % from the source diameter range from 10 mm to 65 mm.