Abstract: 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.

Abstract: An outlet port in the upper end of a fluid flow passageway vertically formed in a flow rate measuring section (8) disposed in a fluid storage recess (23) communicating with a fluid inlet pipe through an opening (21a) communicates with a fluid outlet pipe (22) through an opening (22a). The heat type flow rate sensor (10) disposed in the flow rate measuring section (8) has a fin plate projecting into the fluid flow passageway through a sensor mount hole (8c). The flow rate measuring section (8) is formed with an auxiliary flow passageway for leading the fluid within the fluid storage recess (23) to the inlet port (811) in the lower end of the fluid flow passageway, the auxiliary flow passageway extending in parallel with the fluid flow passageway and having fluid introducing ports (822, 823, 824) and a fluid delivering port (821) leading to the fluid flow passageway.

Abstract: A flow metering method and a flowmeter capable of providing an electric output corresponding to the metered flow rate of metered fluid by an electric circuit including a thermal type flow sensor disposed in a metering flow path and an electric output corresponding to the reference flow rate of the metered fluid by an electric circuit including a reference thermal type flow sensor disposed in a reference flow path allowing the metered flow to flow freely; the flow metering method, comprising the steps of providing a calibration curve including a reference flow calibration curve and a measurement flow calibration curve at a plurality of temperatures for reference fluid beforehand, providing the deviated amount of the temperature of the reference flow calibration curve from the reference temperature corresponding to the electric output based on the electric output corresponding to the reference flow calibration curve based on the deviated amount, and converting the temperature corrected amount to the flow value

Abstract: An outlet port in the upper end of a fluid flow passageway vertically formed in a flow rate measuring section (8) disposed in a fluid storage recess (23) communicating with a fluid inlet pipe through an opening (21a) communicates with a fluid outlet pipe (22) through an opening (22a). The heat type flow rate sensor (10) disposed in the flow rate measuring section (8) has a fin plate projecting into the fluid flow passageway through a sensor mount hole (8c). The flow rate measuring section (8) is formed with an auxiliary flow passageway for leading the fluid within the fluid storage recess (23) to the inlet port (811) in the lower end of the fluid flow passageway, the auxiliary flow passageway extending in parallel with the fluid flow passageway and having fluid introducing ports (822, 823, 824) and a fluid delivering port (821) leading to the fluid flow passageway.

Abstract: A flowmeter comprising 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.

Abstract: A strainer integrated flowmeter 210 is constituted by a strainer section 203 provided with a housing 202 having a flow passage 207 formed therein, a filter member 209 and a filter member insertion cylinder 210; and a flowmeter section 204 provided with a housing 202 having a flow passage 208 formed therein and a flow rate sensor 226. The housings 202 of both the strainer section 203 and flowmeter section 204 are integrated, and the flowmeter section 204 is disposed at downstream side. A vent hole 215 is formed in the housing 202 so as to be in communication with the flow passage 207.

Abstract: A flow metering method and a flowmeter capable of providing an electric output corresponding to the metered flow rate of metered fluid by an electric circuit including a thermal type flow sensor disposed in a metering flow path and an electric output corresponding to the reference flow rate of the metered fluid by an electric circuit including a reference thermal type flow sensor disposed in a reference flow path allowing the metered flow to flow freely; the flow metering method, comprising the steps of providing a calibration curve including a reference flow calibration curve and a measurement flow calibration curve at a plurality of temperatures for reference fluid beforehand, providing the deviated amount of the temperature of the reference flow calibration curve from the reference temperature corresponding to the electric output based on the electric output corresponding to the reference flow calibration curve based on the deviated amount, and converting the temperature corrected amount to the flow value