High temperature in-situ sensing system based on fiber Bragg grating for reciprocating compressor

Abstract cncnA contactless high temperature in-situ sensing system based on fiber Bragg grating(FBG) is proposed to implement accurate temperature measurements of bearing bushing, which is the core component of reciprocating compressor(RC). The system consists of a sensing probe of a FBG putting in a metal capillary to eliminate the cross-sensitivity problem and a pair of optical fiber collimators to send the original optical signal and collect the reflected sensing modulation signal. Considering the intermittent variation of FBG reflection spectrum transmitted by optical fiber collimators with reciprocating relative motion, a demodulation algorithm of wireless FBG signal is proposed and implemented. The experimental results show that the in-situ FBG sensing system has good temperature measurement performance in the range of 10–350 °C, the sensitivity is 9.49pm/°C, and the linearity is more than 99.93%