Patent ID: 7011444

Claim:
A fire heat sensor comprising: a plurality of detecting portions comprising at least three detecting portions mounted in thermal insulation and oriented in portions for receiving heat from hot airflow generated in the case of a fire; at least one of said detecting portions being a low temperature detecting portion comprising a heat accumulator, a heat collector, and a temperature detecting element for measuring and outputting the temperature which rises gradually when heat is received from said hot airflow; at least one of the remaining detection portions being high temperature detecting portion comprising a heat collector and a temperature detecting element for measuring and outputting the temperature which rises rapidly when heat is received from said hot airflow; and a heat sensing circuit for performing differential heat sensing based on the outputs of said at least one low temperature detecting portion and said at least one high temperature detecting portion; wherein said heat collectors achieve thermal insulation by being mounted on a detecting element fixed board which is composed of a material whose thermal diffusivity is less than 10 −6 m 2 /s.