SELF-MONITORING METHOD AND APPARATUS FOR CONDITION MONITORING OF A STRUCTURE

摘要

System 10 for condition monitoring of a structure 12 includes a plurality of cavities 14 formed on an outer surface 16 of the structure 12 and a fluid source 18 at substantially constant pressure which is coupled to the cavities 14 through respective high fluid impedances 20 to create pressure differentials between the source 18 and the cavities 14. System 10 further includes a telemetry system 22 having a plurality of pressure differential switches 42 across each of the high impedances 20 for monitoring for any change in differential pressure across the impedances 20 and, when a change is monitored, providing a signal indicative of the location of the cavity 14 associated with the high impedance 12 across which the change in differential pressure is monitored.The system 10 also includes a fluid capacitance associated with each of the cavities 14 and the corresponding impedances 20 to facilitate a transient flow of fluid through the impedances 20. The transient flow is produced by temporarily coupling the cavities 14 to the reference pressure and then re-coupling to the source 18. This produces transient fluid flow through the fluid capacitance and a consequential transient differential pressure sequentially across each of the high fluid impedance devices 20 thereby inducing sequential cyclical switching of the differential pressure switches 42.