To accurately detect impulse line blockage of a pressure detector for measuring pressure of a fluid via an impulse line, in consideration of the change of a plant gain, in a facility which determines a control output in accordance with a deviation between a target value and a measurement value when controlling pressure of the facility to the target value.
A pressure fluctuation calculation unit 101 calculates a standard deviation of fluctuation of a deviation between a target value and a measurement value of pressure in a detection object period having a prescribed length with respect to time series data of difference between the target value and the measurement value. A correction unit 102 determines a correction value of the standard deviation on the basis of an operation condition and a measurement condition of a facility, and the standard deviation calculated by the pressure fluctuation calculation unit 101 is corrected by the correction value determined by the correction unit 102. A blockage determination unit 103 detects characteristic variation of an impulse line on the basis of time series variation of the corrected standard deviation.
INOUE KEN
AKIO KENGO
