Calibration and Measurement Procedures for a High Magnification Thermal Camera
Brandon M. Lane, Eric P. Whitenton
Infrared thermography is a relatively mature measurement science, however systematic evaluation of measurement uncertainty for multi-point measurement (an infrared focal plane array) is very limited, or, does not follow uncertainty evaluation guidelines outlined in the Bureau International des Poids et Mesures Guide to the Expression of Uncertainty in Measurement (BIPM- GUM). In order to approach uncertainty evaluation of thermographic measurements, a new thermographic calibration and measurement procedure is developed here that takes from procedures used with single-point radiation pyrometer which have a more developed background in uncertainty evaluation. This report details a methodology for calibrating a thermal camera and obtaining temperature measurements, including measurement of surface technique which does not require the camera operating software to convert camera signal to temperature values. In-camera or manufacturer provided calibrations and temperature conversions may provide sufficient measurement precision and accuracy, however these results are often 'hidden' within the camera operating software and are not readily available for thorough analysis, or the methods are known but their form inhibits statistical analyses. The methodology described here is designed as a framework for further development of analytical derivations of thermography measurement uncertainty. The detailed measurement process also includes methods for measuring and reducing identified sources of uncertainty (point spread function) that is otherwise neglected in most thermographic measurement procedures.
thermography, thermal camera, calibration, emissivity, point spread function
and Whitenton, E.
Calibration and Measurement Procedures for a High Magnification Thermal Camera, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.IR.8098
(Accessed May 31, 2023)