Comparison of shortwave and longwave measuring thermal-imaging systems.

ABSTRACT

A comparison study of shortwave (3-5-µm) and longwave (8-12-µm) measuring thermal imaging systems has been conducted. The study was limited to systems working in indoor conditions, as is typical in many industrial and scientific applications. A theory of the influence of measurement conditions and system parameters on the accuracy of temperature measurements has been developed. On the basis of the developed formulas an analysis of the influence of signal disturbances (because of incorrectly assumed emissivity, radiation reflected by the object, radiation emitted by system optics, limited transmittance of the atmosphere, and limited temperature resolution of the system) on the accuracy of temperature measurement has been made. It has been found that the shortwave systems in typical measurement conditions offer generally better accuracy in temperature measurement than the longwave ones do.