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Spectral responsivity calibrations of two type pyroelectric radiometers using three different methods



Jinan Zeng, George P. Eppeldauer, Leonard M. Hanssen, Vyacheslav B. Podobedov


Spectral responsivity calibrations of two different type pyroelectric radiometers have been made in infrared region up to 14 μm in power mode using three different calibration facilities at NIST. One pyroelectric radiometer is a temperature-controlled low noise-equivalent-power (NEP) single-element pyroelectric radiometer with an active area of 5 mm in diameter; the other is a same type pyroleletric radiometer with a dome-input optics, which is designed to increase absorptance and to minimize spectral structures for a flat spectral responsivity. Several calibration facilities at NIST were used to conduct direct and indirect calibrations with high accuracy in spectral regime and absolute scales depending on geometry of radiometers. We report the calibration results for the single-element pyroelectric radiometer using a new Infrared Spectral Comparator Facility (IR SCF) for direct calibration and a combination method of Fourier Transform Infrared Spectrophotometry (FTIS) and tie-point as an indirect approach. For the dome-input pyroelectric radiometer, the results from another direct calibration method using a circular variable filter (CVF) spectrometer and the FTIS are presented as well. The inter-comparison of different calibration methods enables us to improve calibration accuracy and lower uncertainty among facilities. For both radiometers, the consistent results of spectral responsivity have been obtained by different methods from 1.5 μm to 14 μm with the uncertainty between 1 % and 2 % (k=2). Relevant characterization results, such as spatial uniformity, linearity, frequency dependence, are shown. Validation of calibration, uncertainty sources, and improvement for each method will also be discussed.
Proceedings Title
Proceedings of SPIE
Conference Dates
April 23-27, 2012
Conference Location
Baltimore, MD
Conference Title
SPIE Defense, Security & Sensing


Spectral responsivity, single-element pyroelectric radiometer, dome-input pyroelectric radiometer, IR SCF, FTIS, CVF, NEP, reflectance, and absorbance


Zeng, J. , Eppeldauer, G. , Hanssen, L. and Podobedov, V. (2012), Spectral responsivity calibrations of two type pyroelectric radiometers using three different methods, Proceedings of SPIE, Baltimore, MD (Accessed May 19, 2024)


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Created August 15, 2012, Updated February 19, 2017