Optical Fibers For Harsh Environments
With a growing need to monitor processes in harsh environments accurately, optical fibers are becoming an essential element within monitoring systems both as the communication line and as the sensing element.
Optical fiber sensors have been widely adopted into a range of sensing technologies including discrete and continuous temperature, pressure and strain sensors often used in relatively benign environments. Typically these sensors have been used in pipeline monitoring, perimeter monitoring, heat detection and structural monitoring systems, all of which operate within the -45°C to +85°C temperature range of a standard optical fiber. Each of these technologies have competition from other types of sensors, primarily electronic sensors, so adoption rates have been relatively slow.
As industries push their sensing requirements into the high temperature environments in oil wells  and nuclear reactors or into the tight coil requirements for hydrophones and seismic sensing geophones, optical fibers start to offer major technical benefits over electr’onic sensors. Fibers can be designed to tolerate the high temperatures and pressures found in oil wells, they can be radiation tolerant for nuclear environments, are immune to the high levels of Electro-Magnetic Interference (EMI) associated with large industrial machinery and they do not require electrical power at the sensing element, particularly important for subsea reliability.