HEAT CONDUCTION-TYPE SENSOR HAVING INFLUENCE OF TEMPERATURE AND KIND OF FLUID CORRECTED THEREIN, AND HEAT-TYPE FLOW SENSOR AND HEAT-TYPE BAROMETRIC SENSOR USING THE HEAT CONDUCTION-TYPE SENSOR

摘要

There are provided a heat conduction-type sensor that can correct (calibrate) effects of a temperature of a measurement target fluid and a type of the fluid on a measurement value in measurement of a flow velocity, a mass flow, or an atmospheric pressure, and also provided a thermal flow sensor and a thermal barometric sensor that have this correcting function, high sensitivity, and a simple configuration and that are inexpensive.;At least two thin films that are thermally separated from a substrate through the same cavity are provided, one thin film 10 comprises a heater and a temperature sensor, and the other thin film 12 comprises at least one temperature sensor, the temperature sensors being thin-film thermocouples. The thin film 12 is arranged in proximity so that it is heated only through the measurement target fluid by heating of the heater. Calibration circuit means calculates and compares quantities concerning heat transfer coefficients of a standard fluid and the unknown measurement target fluid based on respective pieces of information of a temperature difference between the thin film 12 and a heater temperature measured in both the standard fluid and the unknown measurement target fluid at a predetermined temperature in a state having no flow, absolute temperature information, and others, and correction (calibration) is performed to enable indicating a physical state such as a true mass flow or an atmospheric pressure.