THERMAL TYPE FLOWRATE SENSOR

摘要

PURPOSE: A thermal type flowrate sensor is obtained that secures the temperature of a temperature measurement resistor, and at the same time improves detection sensitivity and reliability. CONSTITUTION: The thermal type flowrate sensor is equipped with a low-thermal capacitance part (13A) that is formed on the surface of a base (1), a heat generation resistance pattern (4) and a temperature measurement resistor (14) that are provided at the low-thermal capacitance part (13A), and a control circuit that applies a constant voltage to the temperature measurement resistor and at the same time supplies a heating current to the heat generation resistance pattern for outputting the heat current as a flowrate measurement signal. The heat generation resistance pattern (4) and the temperature measurement resistor (14) are flatly arranged along a flow direction G of fluid, and the temperature measurement resistor (14) is arranged in the heat generation resistance pattern (4) and at the same time is arranged at an upstream side as compared with the peak position of temperature distribution being generated in the flow direction of the fluid by the heat generation of the heat generation resistance pattern.