Self-monitoring method and apparatus for condition monitoring of a structure

摘要

A system for monitoring a structure includes cavities on an outer surface and a fluid source at substantially constant pressure coupled to the cavities through high fluid impedances to create pressure differentials therebetween. A telemetry system has pressure differential switches across each of the high impedances for monitoring differential pressure changes across the impedances and providing a signal indicative of the location of the cavity associated with the high impedance across which the change is monitored. A fluid capacitance is associated with each cavity and the corresponding impedances to facilitate a transient fluid flow through the impedances. The transient flow is produced by temporarily coupling the cavities to the reference pressure and then recoupling to the source, producing transient fluid flow through the fluid capacitance and a consequential transient differential pressure sequentially across each of the high fluid impedance devices, thereby inducing sequential cyclical switching of the differential pressure switches.