Recent improvements in the fabrication technology of short-wave infrared (SWIR) quantum detectors opened a new era in radiation thermometry. Ambient and higher temperatures can be measured with low uncertainties using thermoelectrically (TE) cooled extended-InGaAs (E-IGA) and short-wave photovoltaic-HgCdTe (sw-MCT) detectors. These detectors, because of their low (2.5 ?m and 2.8 ?m, respectively) cut-off wavelengths, have orders of magnitude lower background noise than traditionally used broad-band infrared detectors such as cryogenically cooled, quantum detectors or thermal detectors. Because of the low detector cut-off wavelength, traditional glass-based optics can be used in the radiation thermometers. To measure low temperatures, the signal measured should be in alternating-current (AC), modulated or chopped, mode to separate it from the background-radiation-produced direct-current (DC) signal and its fluctuations. Design considerations and characteristics of a newly developed SWIR radiation thermometer are discussed. A noise-equivalent temperature difference (NETD) of < 3 mK for a 50 ?C blackbody is found. At the human body temperature of 36 ?C, the measured NETD ? 10 mK indicates that these detectors can be used in non-contact temperature measurements to replace the current thermopile or pyroelectric based radiation thermometers.
Proceedings Title: TEMPMEKO Conference | 2007 |
Conference Dates: May 21-25, 2007
Conference Location: Chateau lake Louise, CA
Conference Title: TEMPMEKO
Pub Type: Conferences
ambient temperatures, infrared, input optics, NEP, NETD, noise, optical radiation, radiance, radiation thermometer