Abstract: This paper introduces the principle and mechanism of the electronic temperature dif-ference and fix sensors.The theoritical analysis of the sensors is given and the design methods according to the different sensitivity requirements of the sensors are proposed.The design, im-plementation and test of a prototype of the electronic temperature difference and fix sensor were fulfilled by using the method proposed in this paper.The success of the prototype research shows that the design method possesses the simplicity,applicability and reliability.

Key words: fire-warning systems, temperature effects, temperature measurements