Shutter-less infrared cameras based on microbolometer focal plane arrays (FPAs) are the most widely used cameras in thermography, in particular in the fields of handheld devices and small distributed sensors. For acceptable measurement uncertainty values the disturbing influences of changing thermal ambient conditions have to be treated corresponding to temperature measurements of the thermal conditions inside the camera. We propose a compensation approach based on calibration measurements where changing external conditions are simulated and all correction parameters are determined. This allows to process the raw infrared data and to consider all disturbing influences. The effects on the pixel responsivity and offset voltage are considered separately. The responsivity correction requires two different, alternating radiation sources. This paper presents the details of the compensation procedure and discusses relevant aspects to gain low temperature measurement uncertainty.

Date Published: 8 June 2015
PDF: 10 pages
Proc. SPIE 9451, Infrared Technology and Applications XLI, 94511F (8 June 2015); doi: 10.1117/12.2177003

Published in SPIE Proceedings Vol. 9451:
Infrared Technology and Applications XLI
Bjørn F. Andresen; Gabor F. Fulop; Charles M. Hanson; Paul R. Norton, Editor(s)