A self-validating differential-pressure flow sensor [using wavelet transforms]

The blockage of the sensing lines of a differential-pressure (DP) flow sensor has been found to be the main cause of malfunction of a flow measurement system in many industrial processes. A novel method based upon wavelet transforms for the self-validation of the DP flow sensor is presented. Unlike a conventional DP flow sensor that provides only measurements, a self-validating version of the sensor developed enables its measurements to be accompanied by a validity index. Namely, the accuracy of the measurement is reflected by the validating uncertainty whilst the normality of the measurement is indicated by normal/abnormal sensor operating status. Experimental results of a designed prototype sensor have verified the effectiveness of the approach.