Practical thermometry with a thermographic camera—calibration, transmittance, and emittance measurements

Abstract

Methods of obtaining quantitative thermometric data with a thermographic camera are discussed. These include the assessment of errors associated with the camera itself and techniques for calibrating the particular camera. Difficulties arising from the nature of the object to be measured also are considered. These include determining the ''penetration of depth'' of infrared radiation emitted by the object (how ''thick'' is the surface?), measuring the transmittance of ''windows'' in front of th objects, and measuring the object's emittance under somewhat adverse circumstances. Finally, an example of a temperature measurement is given. Practical considerations of theromometry are emphasized as opposed to radiometric measurements (such as spectral properties). Examples are drawn from measurements involving tissue-equivalent electromagnetic phantom materials.