Temperature Error Analysis and Parameter Extraction of an 8–14- $\mu{\rm m}$ Thermopile With a Wavelength-Independent Absorber for Tympanic Thermometer

The purpose of this work is to analyze the errors of temperature readings induced by applying the Stefan-Boltzmann law to noncontact tympanic thermometry using 8-14-μm CMOS thermopile infrared sensors and characterize the thermopiles with a wavelength-independent gold-black absorber. The result shows that the temperature errors highly depend on the absorption properties of absorbers and the normalization temperatures. The magnitude of temperature errors in the reading range of 36°C-41°C could be reduced to less than 0.1°C , which meets the requirement of the ASTM standard, for a wide operation temperature range of -10°C-40°C by adopting the 8-14-μm gold-black thermopile. The thermal properties and performance of the gold-black CMOS thermopile were also estimated by the measurements of voltage response and frequency response. The CMOS thermopile shows a high specific detectivity of 1.88×10⁸ cm·Hz^1/2/W and a fast response time of 17 ms.