Fluid consumption amount-measuring method and apparatus for the same

A fluid consumption amount-measuring method for measuring a consumption amount of a pressure fluid for a fluid-operated apparatus connected to a pressure fluid supply source via a stop valve, said method comprising:

• a first step of measuring a pressure value P1 on a downstream side of said stop valve by fully opening said stop valve;
• a second step of measuring a pressure value P2 on said downstream side of said stop valve when an opening degree of said stop valve is adjusted to set a flow velocity of said pressure fluid flowing through said stop valve to be a sound velocity, and connecting a nozzle having a known effective cross-sectional area Sn on said downstream side of said stop valve to measure a pressure value P3 on said downstream side of said stop valve when a part of said pressure fluid is released from said nozzle;
• and
• a third step of calculating an effective cross-sectional area S of a flow passage of said fluid-operated apparatus by using said measured pressure values P2, P3 and said effective cross-sectional area Sn of said nozzle, and calculating said consumption amount Q of said pressure fluid for said fluid-operated apparatus from said calculated effective cross-sectional area S of said flow passage of said fluid-operated apparatus and said measured pressure value P1.