| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a material gas control system capable of diagnosing whether a control state of concentration and flow rate of material gas is abnormal even if a concentration value and a flow rate value of the material gas when a regulating valve is fully opened or closed nearly match set values. <P>SOLUTION: A material gas control system comprises: a housing chamber 10; an introduction pipe 20 which introduces carrier gas; a lead-out pipe 30 which leads out mixed gas composed of material gas and the carrier gas; a first regulating valve 45; a meter which measures concentration and flow rate of the material gas; a first valve control unit 46 which outputs an opening control signal to the first regulating valve 45 so that the concentration value or the flow rate value measured by the meter matches the set value set in advance; a pressure gauge 44 which measures pressure in the housing chamber 10; and a diagnosis unit 47 which diagnoses that the control state of the concentration or the flow rate of the material gas is abnormal when a time change amount of the opening control signal value and a time change amount of the pressure value measured by the pressure gauge 44 meet predetermined conditions. <P>COPYRIGHT: (C)2012,JPO&INPIT |
