Abstract: A flow rate calculation device includes: a specific flow path and a bypass flow path which are provided to branch from a main flow path; a first fluid resistance element which is provided in the specific flow path; a second fluid resistance element which is provided in the bypass flow path; a container which is arranged in the specific flow path; a pressure sensor which detects a pressure in the container; and a flow rate calculation unit. The flow rate calculation unit calculates the flow rate of a first branch fluid diverted to the specific flow path based on a change in the pressure in the container, and calculates the flow rate of the fluid flowing through the main flow path based on the calculated flow rate of the first branch fluid and a diversion ratio determined according to the first fluid resistance element and the second fluid resistance element.

Abstract: A flow rate diagnosis apparatus includes: a main line in which a tank having a volume is provided; a branch line that branches from the main line on an upstream side of the tank; a first open close valve provided in the branch line; a second open close valve provided in the main line; a dead volume defined from the diagnosis object as an upstream end and the first open close valve and the second open close valve as downstream ends; and a second pressure control mechanism that controls a fluid flowing through the main line such that the pressure of the fluid in the dead volume is maintained at a second setting pressure during an inflow mode during which the fluid is caused to flow into the tank by closing of the first open close valve and opening of the second open close valve after a preparation mode.

Abstract: In order to accurately calculate an estimated flow rate by a dynamic constant volume method, a flow rate calculation system including a tank into which fluid flows, an inflow line through which the fluid flows into the tank, and a pressure sensor that detects the pressure inside the tank is adapted to include: a pressure change data storage part that stores pressure change data indicating a temporal change in the pressure detected by the pressure sensor during an inflow period; a flow rate calculation part that calculates the estimated flow rate during the inflow period based on a pressure change rate; and a flow rate correction part that, on the basis of first pressure detected by the pressure sensor after a predetermined time has elapsed after the inflow period and second pressure included in the pressure change data and higher than the first pressure, corrects the estimated flow rate.

Abstract: A flow rate diagnosis apparatus includes: a main line in which a tank having a volume is provided; a branch line that branches from the main line on an upstream side of the tank; a first open close valve provided in the branch line; a second open close valve provided in the main line; a dead volume defined from the diagnosis object as an upstream end and the first open close valve and the second open close valve as downstream ends; and a second pressure control mechanism that controls a fluid flowing through the main line such that the pressure of the fluid in the dead volume is maintained at a second setting pressure during an inflow mode during which the fluid is caused to flow into the tank by closing of the first open close valve and opening of the second open close valve after a preparation mode.

Abstract: In order to accurately calculate an estimated flow rate by a dynamic constant volume method, a flow rate calculation system including a tank into which fluid flows, an inflow line through which the fluid flows into the tank, and a pressure sensor that detects the pressure inside the tank is adapted to include: a pressure change data storage part that stores pressure change data indicating a temporal change in the pressure detected by the pressure sensor during an inflow period; a flow rate calculation part that calculates the estimated flow rate during the inflow period based on a pressure change rate; and a flow rate correction part that, on the basis of first pressure detected by the pressure sensor after a predetermined time has elapsed after the inflow period and second pressure included in the pressure change data and higher than the first pressure, corrects the estimated flow rate.

Abstract: In order to improve a measurement accuracy of a mass flow meter, the mass flow meter comprises a flow rate calculating section that obtains an output signal from a sensor section having a thermosensitive resistive element arranged in a flow channel where a sample gas flows and that calculates a flow rate of the sample gas, a pressure measuring section that measures a primary side pressure in the flow channel, and a flow rate correcting section that corrects the measured flow rate obtained by the flow rate calculating section by the use of the primary side pressure obtained by the pressure measuring section and a gas coefficient determined by an isobaric specific heat of the sample gas.

Abstract: In order to improve a measurement accuracy of a mass flow meter, the mass flow meter comprises a flow rate calculating section that obtains an output signal from a sensor section having a thermosensitive resistive element arranged in a flow channel where a sample gas flows and that calculates a flow rate of the sample gas, a pressure measuring section that measures a primary side pressure in the flow channel, and a flow rate correcting section that corrects the measured flow rate obtained by the flow rate calculating section by the use of the primary side pressure obtained by the pressure measuring section and a gas coefficient determined by an isobaric specific heat of the sample gas.