When using radiation thermometers, it is necessary to set the emissivity of the measured surface on the radiation thermometer before measuring the temperature to obtain the accurate temperature measurement. The aim of this master’s thesis is to evaluate the effective emissivity of the measured surface or sample based on a surface with a known temperature.
In this work the temperature was measured with a contact thermometer, a thermal camera, and a pyrometer. The sample was placed on a plate calibrator, which heated the sample to the desired temperatures. The samples were copper, stainless steel and brass plates coated with different thicknesses of coating.
Some samples were measured twice to establish the repeatability of the measurement. Measurements of copper samples varied significantly with each heating, indicating their instability. Measurements of brass and stainless steel samples did not differ much between the first and second measurements and were therefore suitable for further analysis.
The emissivities in this work are similar to the values of the ones from the literature. Deviations occur due to oxidation and coating on the samples. For copper samples, we could see that the effective emissivity value approaches the value for oxidized copper, further confirming that copper is not stable enough for measurement.
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