EMBEDDED DUAL FIBER BRAGG GRATING SENSOR FOR SIMULTANEOUS MEASUREMENT OF TEMPERATURE AND LOAD (STRAIN) WITH ENHANCED SENSITIVITY

摘要

An embedded dual fiber Bragg gratings sensor for simultaneous measurement of temperature and load (strain) is proposed and experimentally demonstrated. Two nearly identical gratings are mounted on opposite side of an arch-shaped steel strip. The grating in concave and convex position experiences equal blue and red shift, respectively, due to bending of the strip which is exploited in temperature and load (strain) discrimination. The temperature and load (strain) sensitivity of the sensor improves to 28.5 pm/℃ and 2.8 pm/g (2.6 pm/μe). The sensor can measure temperature and load (strain) accurately with small error of ±1℃ and ±1 g, respectively.