Abstract:  Using optical fiber sensor in point type temperature detection for fire alarm，a new point type optical fiber heat fire detector is studied. First, its working principle is analyzed in detail. Then its structure is designed and produced. The experimental results and feasibility analysis are given. The experimental results show that the technical indexes meet the requirements of national standards. Compared with the traditional point type heat fire detectors, the point type optical fiber heat fire detector adopts pure optical method to detect temperature change. Its merit are included in the following points: small temperature measuring components, low cost, good electrical insulation, antielectromagnetic interference, anticorrosion, intrinsic safety, and being conducive to mass production. This optical fiber temperature sensor is especially suitable for fire detection and alarm in places with anti-corrosion, anti-water and intrinsic safety requirements. 

Key words: optical fiber sensor, point type heat fire detector, optical method to detect temperature