Patent attributes
A flowmeter including a flow rate detection circuit including a thermal flow rate sensor (10) disposed in a measurement flow passage through which fluid to be measured passes, a temperature sensor circuit (12), a flow rate conversion circuit and a storage means EEPROM. The storage means stores, for respective discrete temperature values, a plurality of individual calibration curves indicating the relationship between electric outputs from the flow rate detection circuit and flow rates, and the individual calibration curves are prepared by using flow rates converted into those at a reference temperature. The flow rate conversion circuit performs interpolation based on temperatures measured by the temperature sensor circuit (12) and a plurality of individual calibration curves to obtain calibrated flow rate values corresponding to temperature at measuring.