Abstract: A flow rate controller detects a clogged state of an orifice to prevent errors during flow rate measurement. The flow rate controller includes a differential pressure flow meter, with an orifice disposed between a pair of pressure sensors, that converts a pressure difference detected by the two pressure sensors into a flow rate, a flow-rate adjusting valve whose degree of opening is controlled such that the difference between a measured flow rate value and a preset flow rate value falls within a predetermined range, and a control unit that controls the degree of opening of the flow-rate adjusting valve upon receiving the pressure values detected by the pressure sensors. The control unit compares the preset flow rate value and the measured flow rate value and determines that there is a clog fault when a flow rate difference, as compared with a predetermined value, continues for a predetermined time period.

Abstract: A flow rate controller detects a clogged state of an orifice to prevent errors during flow rate measurement. The flow rate controller includes a differential pressure flow meter, with an orifice disposed between a pair of pressure sensors, that converts a pressure difference detected by the two pressure sensors into a flow rate, a flow-rate adjusting valve whose degree of opening is controlled such that the difference between a measured flow rate value and a preset flow rate value falls within a predetermined range, and a control unit that controls the degree of opening of the flow-rate adjusting valve upon receiving the pressure values detected by the pressure sensors. The control unit compares the preset flow rate value and the measured flow rate value and determines that there is a clog fault when a flow rate difference, as compared with a predetermined value, continues for a predetermined time period.