The paper shows the successful implementation of a process diagnostic function in a differential pressure transmitter and its integration in a control system. This type of instrument is widely used in the industry for flow measurement applications. It is connected to the process through two pipes called impulse lines. During the operating life of the transmitter, these connections can get plugged due to solid material present in the process, limestone or freezing of the fluid, causing significant maintenance effort. Experiments showed that the plugging condition can be diagnosed analysing the sensed differential pressure signal. Based on these results, a method for the automatic detection of the plugged-impulse-lines condition was developed and an algorithm utilizing this method was implemented into a differential pressure transmitter. The new algorithm is based on the spectral analysis of the differential pressure signal. It is self-adaptive to the specific process conditions at the time of installation. It is able to detect the plugged-impulse-lines events with a certain degree of robustness with respect to variations of the process conditions. It proved to be applicable for both liquids and gases. Special care was taken for avoiding false alarms and having at the same time good diagnosis effectiveness. Several field tests proved the usability of the plugged-impulse-line detection function in industrial applications. The availability of the diagnostic information through a control system has a significant impact on plant maintenance cost.
Embedded diagnosis to detect plugged impulse lines of a differential pressure transmitter
Eingebettete Diagnose zur Entdeckung verstopfter Anschlußleitungen eines Differenzdruckwandlers
2006
4 Seiten, 6 Bilder, 5 Quellen
Conference paper
English
Embedded diagnosis for pressure transmitter
IuD Bahn | 2007
|Engineering Index Backfile | 1944
|Engineering Index Backfile | 1944
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