Decay-slope method for 2-dimensional temperature field measurement using thermographic phosphors

In this study, a simple and fast data analysis method using the decay-slope of phosphorescence was suggested for the phosphor thermometry to obtain instantaneous temperature field in high and a wide range of temperature. Mg4FGeO6:Mn was used as TP, and pulsed UV-LED and a CMOS high speed camera with 4000 frames per second were used for the phosphor thermometry. A data processing procedure for pixel by pixel in-situ calibration and temperature measurement was also suggested. To reduce data processing time and uncertainty, the interrogation window concept was introduced. Post-processing of the calibration and experimental data was analyzed using MATLAB, and a number of concepts that could reduce the computation time remarkably were suggested. Comparison of performances in both the decay-slope analysis and the lifetime analysis was made with the same number of data. As a result, the decay-slope method improved computation time more than 23 times faster than that of the lifetime analysis and the calibration accuracy was similar for both methods.