THERMAL-TYPE FLOW RATE SENSOR

摘要

PURPOSE:To reduce an error due to heat radiation from a flow velocity probe and at the same time to obtain a thermal-type flow rate sensor which has a superior response. CONSTITUTION:The sensor is placed in a fluid while a flow velocity probe 21 is supported at one edge and measures the flow velocity and the flow rate of the fluid according to the amount of heat which is released corresponding to the flow velocity of the fluid. The flow velocity probe 21 is provided with a supporting base 211 which is electrically insulated and is formed into a slender shape and a film-shaped thermal resistor 212 which is attached to the surface of the supporting base 211. The thermal resistor 212 consists of a main thermal part 212A with a negative resistance temperature coefficient and a thermal buffering part 212B which is placed below the lower edge of the main thermal part 212A and has a positive resistance temperature coefficient.