The fiber optic temperature measurement system is a new technology that realizes real-time measurement of the spatial temperature field distribution by using certain characteristics of light transmitted in the fiber. It performs distributed continuous detection of the temperature along the fiber — the fiber itself is the temperature sensor. This technology is very suitable for temperature detection of electrical equipment and can be used together with the fire alarm system for online temperature detection of primary current-carrying equipment in the power supply system. It will enrich the content of the "five remotes" monitoring system of substations and has broad application prospects in power plants and substations.

The distributed fiber optic temperature sensor system (commonly known as the fiber optic temperature measurement system) is a sensor system for real-time measurement of spatial temperature field distribution. The system relies on time-domain reflectometry (OTDR) technology and laser Raman spectroscopy analysis technology, and uses wavelength division multiplexers, optical detectors, etc. to amplify and process the collected temperature information, and display the temperature information in real time. This technology was first proposed by the University of Southampton in the UK in 1981. At present, foreign countries (mainly the UK, Japan, etc.) have developed distributed fiber optic temperature sensor products using the laser Raman spectroscopy effect. China is also actively carrying out research in this area, has developed a product series of distributed fiber optic temperature sensors, and has achieved initial application in some industrial fields with very ideal results.

Distributed fiber optic sensor technology has the characteristics of anti-magnetic-field interference and wide signal transmission bandwidth. It can continuously measure the temperature along the fiber, with a measurement distance of several kilometers and spatial positioning accuracy at the meter level, and can achieve uninterrupted automatic measurement. It is especially suitable for applications requiring large-scale multi-point detection. In the power supply system, this fiber optic sensing technology has broad application prospects in temperature sensing of high-voltage power cables, positions of electrical equipment prone to heating due to poor contact, cable compartments, cable channels, diesel generator stators, large transformers, boilers and other infrastructure.