Horiba Stec, Co., Ltd.

Toshihiro Kashima

Yuki Tanaka

Tatsuya Hayashi

Yutaka Yoneda

Yasuhiro Isobe

Kohei Honda

Provided is a flow rate ratio control device that even in change periods during which the actual flow rates of component gases change along with a change in the target total flow rate or target mixing ratio of mixed gas, can keep the actual total flow rate or actual mixing ratio of the mixed gas constant. Target flow rates set in flow rate control devices have continuous change periods during which target flow rate values continuously change from pre-change to post-change target flow rate values, respectively and correspondingly; and the time lengths of the continuous change periods are set to at least a followable time during which a flow rate control device of which a response speed to an actual component fluid flow rate is lowest allows the actual component fluid flow rate to substantially follow the target flow rate in the continuous change periods.

Flow rate ratio control apparatus and program for flow rate ratio control apparatus

A mass flow controller comprises a flow rate measuring part that measures a flow rate of a fluid flowing in a flow channel and outputs a measured flow rate value, a control valve, a valve control part that controls an opening degree of the control valve based on an entirely-close command to entirely close the control valve compulsorily or a set flow rate value set as a target value, and an external output part that outputs an external output flow rate value based on the measured flow rate value to the outside, and at a time when the valve control part receives the entirely close command or zero as the set flow rate value, the external output part outputs zero as the external output flow rate value, irrespective of the measured flow rate value.

Flow rate control device

An object of this invention is to provide a superior mass flow meter or the like that can flexibly cope with a change of a sample fluid such as a gas kind without requiring a special troublesome labor and that can measure a flow rate with high accuracy. The mass flow meter comprises a sensor section that detects a flow rate of a sample fluid flowing in a flow channel, a setting section that sets a flow rate characteristic function that is intrinsic to each fluid to determine a flow rate based on a flow rate detected value output by the sensor section and an instrumental error correction parameter that is independent from the flow rate characteristic function and common to multiple sample fluids to correct an instrumental error of each mass flow meter, and a flow rate calculating section that calculates a flow rate measurement value of the sample fluid by applying the flow rate characteristic function and the instrumental error correction parameter to the flow rate detected value.

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Kyoto, Japan

Toshihiro Kashima