Thermal imaging system applying two-color thermometry

This study deals with a new thermal imaging system using the principle of two-color thermometry to determine the temperature of objects without assigning their emissivity. This is an advanced system of conventional thermography and it was proposed in our previous study. Applying two-color thermometry to conventional thermography is performed by dividing the detectable wavelength range of a thermograph into two different ranges using respective band-pass filters. A thermal image is constructed from the two energy distributions of radiation which are measured after passing through each filter. In this study, in order to improve the accuracy of imaged temperature in the present system, a new thermal image processing which takes account of the background radiation has been proposed. This study also numerically investigates the effect of the filters' radiative characteristics on the accuracy of imaged temperature and clarify optimum characteristics of the filters.