We presented two methods of experimental determination of effective emissivity. The first follows the definition where emissivity is the ratio of surface radiation intensity to black body radiation intensity under the same conditions (temperature, spectral characteristics of the sensor, geometrical conditions). The second method is adjusting the effective emissivity setting on the radiation thermometer until the measured radiation temperature equals the true temperature of the target (accurately measured with a contact thermometer).
In the experiment, we used both described radiometric methods to determine the factor of emissivity. We obtained and organised the results into tables and created graphs from them, which we then analysed, and concluded that with the calculation method the final values of the effective emissivity converge with increasing temperature. These are close to the values of the adjustment method but are almost constant during the measurement.
|