ABSTRACT

Sensing of a variable is essential for measurement and control of any process. The large number of variables encountered are measured by a variety of electrical, electronic, pneumatic, hydraulic, and other devices. Fiber-optic (FO) sensors are replacing some of these conventional sensors in some areas. FO sensors offer many advantages over conventional sensors. Some of these are the freedom from electromagnetic interference (EMI) due to the lack of electrical bias at the sensor; the capability of working in harsh environments contaminated with explosives, and corrosive gases (because FO sensors are chemically inert); compatibility with telemetry, and easy integrability with semiconductor devices; low weight and hence better frequency response over a wider range; low power consumption; capability of offering higher accuracy in measurements; the capability of multielement sensor systems of supporting a large number of high-bandwidth sensor elements; and the elimination of the requirement of transmitting electrical power remote from the monitoring site.