Experimental Study of Temperature Sensitive Dyes for Planar Laser Induced Fluorescence Thermometer

As a non-intrusive, whole-field temperature measurement technique, LIF (Laser Induced Fluorescence) has been used successfully to measure temperature fields. The performances of dyes are essential of the technique, especially the temperature sensitivity of the dyes. This work presents an analysis to provide a correct choice of temperature sensitive dyes combination (FL27 and RhB). The influences of temperature, excitation wavelength and pH on emission intensity and temperature sensitivity were analyzed. The results show that the temperature dependent tendency of FL27 changed from negative to positive as the excitation wavelength increased. The temperature sensitivity (4.0% per °C) of combination under 532nm laser is better than that of the wide used combination of RhB and Rh110 (2.0% per °C). The emission intensities of dyes are sensitive to pH value; however, the temperature dependence is unaffected.