Optical-fiber sensors challenge the competition: Resistance to corrosion and immunity to interference head the list of benefits in detecting stimuli ranging from pressure to magnetism

Optical-fiber sensors are reviewed for the measurement of temperature, pressure, acceleration, flow of liquids and gases, and the level of a liquid in a container. Optical-fiber sensors are making their first commercial appearance in measuring instruments and controls where such attributes as sensitivity, resistance to hostile environments, and compactness are essential. Through alteration of light by external stimuli, these sensors can now detect virtually any stimulus the other sensors can-from pressure and magnetism to acidity and acceleration-and often more sensitively and accurately, and over a wider dynamic range. Optical-fiber sensors are more rugged and more resistant to corrosion than other sensors, immune to electromagnetic interference, and compatible with optical-fiber telemetry. Several types of fibre sensors that are in commercial production, being field-tested, and in advanced development are discussed.