Issue << content << Determination of the Thermal Radiation Coefficient Using Digital Camera at an Active Thermal Inspection of Metal


2014. . No. 4(66) - Dec 2014, pp. 76-79

Determination of the Thermal Radiation Coefficient Using Digital Camera at an Active Thermal Inspection of Metal

V. N. Slavkov, A. P. Davidenko

Methods and algorithms for processing images obtained by a digital camera were developed. Thermal radiation images of the metallic plates (stainless steel) at high temperatures have established the spatial distribution of the thermal radiation coefficient. MathCAD software and LabVIEW were used to develop the algorithms. An experimental setup has been developed which included the combined method of object temperature measuring: pin, using thermoelectric converters, and remote, with the use of a digital camera. Before setting up the experiment, a measuring part of the apparatus was calibrated, and the functional dependence of the brightness temperature on the red component value of digital camera images was pre-set, using a standard black body. According to the results of digital image processing two-dimensional and one-dimensional graphical representation of the thermal radiation coefficient were built. It is noted that the developed method is universal and allows establishing the spatial distribution of the thermal radiation coefficient for different kinds of metals at different temperatures and wavelengths. As a result, at the procedure of thermal inspection it is possible to significantly improve the accuracy of the results through a proper accounting of the thermal radiation coefficient. In addition, this method has sufficiently high resolution.
Keywords: thermal radiation coefficient, digital SLR camera, black body, heat inspection, stainless steel, CCD, red channel component, MathCAD, LabVIEW
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