APPARATUS AND METHOD FOR LOCATING A MEASURAND ANOMALY ALONG A WAVEGUIDE

An apparatus for locating a measurand anomaly, such as a hot-spot, along an optical waveguide is provided having: an optical waveguide, a light source configured to transmit light along the waveguide and a plurality of sensors provided along the waveguide. Each sensor is configured to reflect a portion of light propagating along the waveguide at a respective sensor wavelength corresponding to a measurand. The plurality of sensors is configured into one or more sets according to their sensor wavelengths, each set comprising a plurality of sensors with respective sensor wavelengths, wherein the sensors are configured such that the sensor wavelength for each sensor in a respective set is substantially equal when the measurand experienced by each of the sensors in that set is equal. The apparatus further includes a detector configured to monitor the light reflected by the sensors, and a control system.