Abstract: In order to prevent unnatural behavior of a calculated flow rate, provided is a fluid control device in which a fluid control valve and upstream and downstream pressure sensors are provided on a flow path. The device includes a calculation unit configured to calculate a flow rate based on measured pressures; and an output unit configured to output the calculated flow rate, and exhibit a zero output function of outputting a zero value regardless of the calculated flow rate when the valve is in a closed state. The device is further configured to switch between execution and stop of the zero output function, and when the valve is in an open state and a difference between the measured pressures of the pressure sensors is larger than a threshold, stop the zero output function and cause the flow rate output unit to output the calculated flow rate.

Abstract: A fluid control device includes a fluid resistance element provided to a channel, an upstream pressure sensor configured to detect an upstream pressure of the fluid resistance element, a downstream pressure sensor configured to detect a downstream pressure of the fluid resistance element, a flow rate calculating unit configured to calculate a flow rate flowing through the channel based on the upstream and downstream pressures, a valve provided upstream of the upstream pressure sensor or downstream of the downstream pressure sensor, and a valve control unit configured to control the valve based on the calculated flow rate. When the valve is fully closed, the flow rate calculating unit is configured to calculate the flow rate by switching a first flow rate calculation formula that is used when the valve is open, to a second flow rate calculation formula that is different from the first flow rate calculation formula.

Abstract: In order to prevent unnatural behavior of a calculated flow rate, provided is a fluid control device in which a fluid control valve and upstream and downstream pressure sensors are provided on a flow path. The device includes a calculation unit configured to calculate a flow rate based on measured pressures; and an output unit configured to output the calculated flow rate, and exhibit a zero output function of outputting a zero value regardless of the calculated flow rate when the valve is in a closed state. The device is further configured to switch between execution and stop of the zero output function, and when the valve is in an open state and a difference between the measured pressures of the pressure sensors is larger than a threshold, stop the zero output function and cause the flow rate output unit to output the calculated flow rate.

Abstract: A verification system includes a reference gas supply part that supplies reference gas in place of exhaust gas and is configured to be able to verify the consistency between a supply amount of the reference gas from the reference gas supply part and a measured value of the reference gas measured by an analyzer. The verification system further includes a control part that receives a setting flow rate signal that is a signal indicating a setting flow rate and an analysis range signal that is a signal indicating an analysis range of the analyzer, calculates a target supply amount of the reference gas on the basis of the setting flow rate and the analysis range indicated by the respective signals, and controls the reference gas supply part so as to make the reference gas supply amount by the reference gas supply part equal to the target supply amount.

Abstract: A verification system includes a reference gas supply part that supplies reference gas in place of exhaust gas and is configured to be able to verify the consistency between a supply amount of the reference gas from the reference gas supply part and a measured value of the reference gas measured by an analyzer. The verification system further includes a control part that receives a setting flow rate signal that is a signal indicating a setting flow rate and an analysis range signal that is a signal indicating an analysis range of the analyzer, calculates a target supply amount of the reference gas on the basis of the setting flow rate and the analysis range indicated by the respective signals, and controls the reference gas supply part so as to make the reference gas supply amount by the reference gas supply part equal to the target supply amount.

Abstract: The present invention is provided with a control device that sets a split flow ratio that is a ratio of the flow rate of the diluted exhaust gas to be sampled through a diluted exhaust gas sampling flow path to a flow rate of a diluted exhaust gas flowing through a CVS, wherein the control device uses the flow rate (QCVS) of the diluted exhaust gas flowing through the CVS or a value (TCVS or PCVS) related to the flow rate (QCVS) of the diluted exhaust gas to set the split flow ratio (Qsamp/QCVS) so as to make a flow velocity (Vfilter) of the diluted exhaust gas flowing into an analytical device equal to a predetermined value.

Abstract: The present invention is provided with a control device that sets a split flow ratio that is a ratio of the flow rate of the diluted exhaust gas to be sampled through a diluted exhaust gas sampling flow path to a flow rate of a diluted exhaust gas flowing through a CVS, wherein the control device uses the flow rate (QCVS) of the diluted exhaust gas flowing through the CVS or a value (TCVS or PCVS) related to the flow rate (QCVS) of the diluted exhaust gas to set the split flow ratio (Qsamp/QCVS) so as to make a flow velocity (Vfilter) of the diluted exhaust gas flowing into an analytical device equal to a predetermined value.