Patent ID: 7650245

Claim:
An impulse line-clog detecting apparatus comprising: a differential pressure detecting unit that detects a differential pressure of a fluid based on a high pressure transmitted via a high pressure side impulse line and a low pressure transmitted via a low pressure side impulse line, and outputs time-series data of the differential pressure; a differential pressure fluctuation calculating unit that calculates a differential pressure fluctuation based on the time-series data of the differential pressure; a fluctuation variance calculating unit that calculates a variance of the differential pressure fluctuation; a variance ratio calculating unit that calculates a variance ratio of the differential pressure fluctuation variance calculated by the fluctuation variance calculating unit to a differential pressure fluctuation variance obtained in advance in a normal state of the high pressure side impulse line and the low pressure side impulse line; a variance ratio connecting unit that calculates a correction value for suppressing change of the variance ratio, which is caused by change of a flow rate of the fluid, based on the differential pressure time-series data output from the differential pressure detecting unit and time-series data of the differential press obtained in advance in the normal state, and corrects the variance ratio based on the correction value; and a clogging determining unit that determines whether the high pressure side impulse line and the low pressure side impulse line are clogged, based on the variance ratio corrected by the variance ratio correcting unit.