LAUSR

In this paper, we present dual-channel lock-in phosphor thermometry, which offers an option of accurate and contactless temperature determination under high environmental noise. We studied YAG:Dy as thermographic phosphor at an excitation wavelength of 405 nm. We tested our approach under different experimental conditions with noise levels of about 550, 1060 and 2190 times larger than the excitation signal. With the dual-channel lock-in setup, we were able to suppress the strong noise in all cases and to reliably determine surface temperature using our optical measurements (error < 10 K). Additionally, the effect of signal to noise ratio, lock-in frequency and lock-in bandwidth on temperature determination accuracy was studied in this work.