Two-dimensional lifetime-based kHz surface temperature measurement technique using phosphor thermometry

A kHz phosphor thermometry technique was developed for contactless two-dimensional measurements with Mg4FGeO6: Mn4+ utilizing its rise and decay of the phosphorescence. Different from the traditional method that phosphorescence rises when the decay is complete, high-frequency excitation light was applied in this study, which causes a rise of phosphorescence with an incomplete decay of phosphorescence. This eventually causes the phosphor to emit a waveform signal. Experimental results show that this phosphorescence waveform signal is stable and only affected by temperature when the excitation conditions are fixed. A calibration curve can then be obtained by calculating the ratio of the crests and troughs of the phosphorescence signal. This study shows that the developed method has high precision and is easy to operate for two-dimensional high-frequency temperature measurement.