Study on optical fiber temperature sensor using two-wavelength light sources

An optical temperature sensor is presented, which adopts two-wavelength light sources and is for the on-line detection of the temperature in high voltage facilities. This system is based on the spectrum absorption characteristics of semiconductor. Optical fiber and optical passive device are employed to detect and transfer temperature signal. The sensor is immune to electro-magnetic interference, and possesses high insulation level. Improved two-wavelength compensating method was used. The measuring system can eliminate the disturbance effect in the optical path of sensor, thus the problem of instability is solved and measurement precision is greatly enhanced. The experimental results identified the correctness of theoretical investigation.