The AE monitoring approach is based on a limited number of AE sensors, coupled to the headers by means of welded waveguides, and on the use of real-time AE source location to discriminate between significant and non significant AE sources; AE source location is limited to the axial coordinate along the header. The limited number of sensors and simplified signal procedures enable to achieve real-time operation and affordable AE equipment costs and limits the amount of data to be processed, locally stored and transmitted to a modem-connected remote monitoring station.
Long-term monitoring of the above components has been proven to be feasible, in terms of both background noise behaviour and instrumentation reliability. A variety of plant operating conditions has been investigated (steady load, load variations, startup/shutdown transients) and consistently correlated with recorded AE activity. On the basis of normal AE activity patterns, preliminary guidelines for diagnostic evaluation of AE activity have been outlined. A few significant deviations from normal AE behaviour, possible correlated to already recognized structural problems in assembly welds, have also been recorded by the monitoring system, to be checked for further confirmation during next planned maintenance shutdowns.
It is recommended that more applications are systematically undertaken to build up a database of significant monitoring case histories, to enhance the diagnostic reliability of the method as a structural risk management tool. This work has been carried in the frame of BRITE-EURAM Project 6056 "SIMON", with the financial support of the UE Commission.
Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00
Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:
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