Design of Coal Mined Zone Temperature Detector Based on Optic Absorption Principle

Based on the principle of optical absorption of semiconductor variation with temperature, a method of optical-electrical testing for coal mined zone is proposed. The measurement of the reflecting light intensity is utilized in the method. Also a hardware circuit and FFT data processing technology for coal mined zone temperature measuring system based on optic absorption principle is introduced emphatically. FFT technique can improve signal-to-noise ratio, the hardware structure of the system has been greatly simplified and at the same time the anti-interference capacity is enhanced. The theories and experiments show that the proposed system has characteristics of wide measurement range, high precision, good real-time performance, small volume, low-cost. Both the precision and real-time property can meet the demand of the actual application. And the system after a slight modification also suits for other temperature detection under special working condition such as strong electromagnetic interference, combustible and explosive area, narrow space.