Horiba Stec, Co., Ltd.

Hiroyuki Okano

Takashi Shirai

Atsushi Ieki

Hidetoshi Emura

The present invention provides a thermal flow meter that includes a sensor flow path along which flows a fluid being measured, an upstream-side electrical resistance element provided on the sensor flow path, a downstream-side electrical resistance element provided downstream of the upstream-side electrical resistance element, a sensor output generator that, based on respective voltages that are output in accordance with changes in the upstream-side and downstream-side electrical resistance elements, generates a sensor output in accordance with the flow rate of the fluid being measured, a slope effect estimator that, based on at least a Prandtl number of the fluid being measured, estimates a slope effect that is generated in the sensor output in accordance with an attitude of the sensor flow path, and a flow rate calculator that corrects the slope effect from the sensor output, and calculates the flow rate of the fluid being measured.

Thermal flow meter, flow rate control device, thermal flow rate measurement method, and program for thermal flow meter

In order to provide a correction device that enables the accuracy of the linearity between sensor output values and flow rate values in a flow rate sensor, there are provided a sensitivity correction function storage unit that stores a sensitivity correction function in which at least a portion of sensitivity correction values are set to different values in accordance with the sensor output values output from a flow rate sensor in an initial state in which the sensitivity coefficient is set to an initial value, a sensitivity setting unit that sets the sensitivity coefficient based on the initial values and on the sensitivity correction function, and then adjusts the sensitivity of the flow rate sensor, and a coefficient calculation unit that calculates a post-correction flow rate characteristic function based on function correction values that are decided in accordance with the flow rate values output post sensitivity correction.

Flow rate sensor correction device, flow rate sensor, flow rate control device, program recording medium on which is recorded a program for a correction device, and correction method

In a flow path forming structure, axial runout of a shaft relative to a central axis generated when the shaft is inserted into the flow path is suppressed. This structure includes a flow path along which a fluid passes, and a shaft body that is inserted into the flow path. An upstream side of the shaft body and an inner circumferential surface of the flow path have a plurality of contact positions at different phases, and a downstream side of the shaft body and an inner circumferential surface of the flow path have a plurality of contact positions at different phases. The fluid flows through gaps between the shaft body and the inner circumferential surface. The contact positions on one of the upstream and downstream sides are at different phases from all of the contact positions on the other one of the upstream and downstream sides.

Flow path forming structure, flow rate measuring device and flow rate control device

A thermal flow meter is provided that can accurately correct zero point and span errors, which change depending on an ambient temperature, independently of a fluid type. The thermal flow meter includes: a flow path through which measuring target fluid flows; an upstream side electrical resistive element provided on the upstream side of the flow path; a downstream side electrical resistive element provided on the downstream side of the flow path; and a flow rate calculation part that calculates a flow rate of the measuring target fluid on the basis of an upstream side voltage that is a voltage applied to the upstream side electrical resistive element, a downstream side voltage that is a voltage applied to the downstream side electrical resistive element, and the thermal conductivity of the measuring target fluid.

Thermal flow meter, temperature measurement device, and thermal flow meter program

In order to reduce a flow rate error over the entire range of a sensor output value even when the relationship between the sensor output value and a flow rate value is poor in linearity, a flow rate sensor correction device includes: a sensitivity setting part adapted to set a sensitivity coefficient on the basis of an initial value and a sensitivity correction value and adjust the sensitivity of the flow rate sensor; a function calculation part adapted to calculate a corrected flow rate characteristic function on the basis of a function correction value, which is determined on the basis of the flow rate value, and a standard flow rate characteristic function; and a function modification part adapted to make a function storage part store, as a flow rate characteristic function, a final flow rate characteristic function based on the corrected flow rate characteristic.

Flow rate sensor correction device, program for correction device, and correction method

The present invention is configured to, on the basis of an upstream side parameter having a value that is related to a change rate of an upstream side voltage when a flow rate of measuring target fluid changes, and a downstream side parameter having a value that is related to a change rate of a downstream side voltage when the flow rate of the measuring target fluid changes, calculate a fluid-specific value exhibiting a specific value depending on the thermal conductivity of the fluid.

Fluid analysis device

A thermal flow rate sensor is provided which includes a main flow path through which a fluid flows, and a sensor flow path that branches off from the main flow path so as to cause the fluid to flow in a split flow and that is provided with a flow rate detecting mechanism configured to detect a flow rate of the fluid. The flow rate detecting mechanism includes an upstream-side coil and a downstream-side coil, each configured by using a heat-generating resistance wire wound around a sensor flow pipe forming the sensor flow path. A peak position of a temperature distribution generated in the sensor flow path by the upstream-side coil and the downstream-side coil is positioned on the upstream-side coil side relative to the middle position between the upstream-side coil and the downstream-side coil on the sensor flow path.

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Kyoto, Japan

Hiroyuki Okano