微波冷冻干燥过程中光纤测温技术的研究

Investigation on the Temperature Measurement in Microwave Freeze Drying Process Using Optic Fiber Sensor

分析了半导体吸收波长随温度的变化特性，选用红外发光二极管作为信号光源，光纤采用石英光纤，设定这类半导体吸收式光纤温度传感器的基本参数，建立了半导体材料ＧａＡｓ的透过率与温度关系的数学模型．采用一种基于双波长原理的输送回路来减少测量误差，研制成功了一套半导体吸收式光纤测温系统．在０～１００℃内进行了实验测试．结果表明。

A new type of fiber optic temperature sensor was developed to measure the temperature in a microwave field. The variation of wavelength with temperature was analyzed. Two infrared light emitting diodes with the peak wavelength 880 nm and band width 40 nm were used as a light source. The diameter of quartz fiber is 0.5 mm and the thickness of GaAs piece is 0.15￣0.20 mm. The diameter of the sensor is about 4 mm. A mathematical model of the relationship between penetrability and temperature was deve loped and all working parameters were set up. An optic transfer circuit based on the two wavelength principle was designed to decrease the measuring error. The temperature measurement was conducted in a range of 0￣100℃. The results show that the optic fiber sensor developed in this work could be used to measure local temperature of the object under the microwave field after further improvement.