Fiber-Optical Magnetic Sensor Employing AC Phase Modulation

• Main Authors: Chih Long Yang, 楊志龍
• Other Authors: Chia Nan Chang
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/85333398396404804921

碩士 === 國立臺灣科技大學 === 工程技術研究所 === 82 === Optical fiber sensors have many advantages over conventional ones.Among them are small size, high sensitivity, resistance to high temperature, inherent safety, immunity to electromagnetic interference, and so on. As magnetic field measurement is of increasing important, a fiber optic magnetic field sensing system is studied in this work. A Mach-Zehnder interferometer is utilized in this system and a magnetostrictive transducer 2605SC as our sensing element. In experiments, a piezoelectric transducer (PZT) is used to do AC phase modulation. Two technologies of detection system are investigated. One is phase tracking with AC(PTAC).The other is passive homodyne(HOM) detection system. The linearity, frequency response, the effect of DC bias to AC field measurement of this system are studied. When AC field of frequency 1KHz is added, the system has been proved to be capable of measureing magnetic field below 0.00479 Oersted .