The influence of the spectral emissivity of flat-plate calibrators on the calibration of IR thermometers

Journal Article · Wed Sep 11 00:00:00 EDT 2013 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4819636· OSTI ID:22218045

Cárdenas-García, D.; Méndez-Lango, E. ^[1]

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1. Centro Nacional de Metrología, CENAM Km 4.5 Carretera a los Cués, El Marqués, Querétaro, 76246 (Mexico)

Flat Calibrators (FC) are an option for calibration of infrared thermometers (IT) with a fixed large target. FCs are neither blackbodies, nor gray-bodies; their spectral emissivity is lower than one and depends on wavelength. Nevertheless they are used as gray-bodies with a nominal emissivity value. FCs can be calibrated radiometrically using as reference a calibrated IR thermometer (RT). If an FC will be used to calibrate ITs that work in the same spectral range as the RT then its calibration is straightforward: the actual FC spectral emissivity is not required. This result is valid for any given fixed emissivity assessed to the FC. On the other hand, when the RT working spectral range does not match with that of the ITs to be calibrated with the FC then it is required to know the FC spectral emissivity as part of the calibration process. For this purpose, at CENAM, we developed an experimental setup to measure spectral emissivity in the infrared spectral range, based on a Fourier transform infrared spectrometer. Not all laboratories have emissivity measurement capability in the appropriate wavelength and temperature ranges to obtain the spectral emissivity. Thus, we present an estimation of the error introduced when the spectral range of the RT used to calibrate an FC and the spectral ranges of the ITs to be calibrated with the FC do not match. Some examples are developed for the cases when RT and IT spectral ranges are [8,13] μm and [8,14] μm respectively.

• OSTI ID: 22218045
• Journal Information: AIP Conference Proceedings, Vol. 1552, Issue 1; Conference: 9. international temperature symposium, Los Angeles, CA (United States), 19-23 Mar 2012; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ABSORPTION SPECTROSCOPY
CALIBRATION
EMISSIVITY
FOURIER TRANSFORM SPECTROMETERS
FOURIER TRANSFORMATION
INFRARED SPECTRA
INFRARED SPECTROMETERS
PLATES
RADIOMETERS
THERMOMETERS
WAVELENGTHS