Measurement of Surface Temperature and Emissivity with Dual-Colour Stereo Thermography

This work proposes an application of the dual-colour thermometry principle to IR thermography, by using two IR cameras with detectors working into two different wavelength ranges and by processing IR images with the pinhole camera calibration model. With the two radiation distributions measured by thermographs it is possible to write a system of equations in which emissivity and temperature are unknown quantities. By solving the system, temperature and directional emissivity of the material under test can be measured. The influence of random and biased error on the proposed methodology has been numerically analyzed. To validate the proposed methodology some tests are performed on body with emissivity measured in conventional way. Experimental results show good agreements between emissivity values measured with the proposed methodology and with standard measurements.