System fault discriminating electrostatic engine diagnostics

Claim 1

Electrostatic diagnostic apparatus for distinctly correlating different events occurring in an operating gas turbine engine, comprising: electrostatic signal means, including a probe to be disposed in the gas stream of an engine, for providing, when said probe is disposed in the gas stream of an operating engine, a probe signal having a waveshape defined by amplitude variations thereof across a time interval of a given duration in response to electrostatic charge flowing in the gas stream in the vicinity of said probe; and signal processing means connected for response to said electrostatic signal means, for selectively providing a particular engine event identifying signal selected, in response to said amplitude variations across said time interval, from among a plurality of identifying signals in dependence on the waveshape of said probe signal having characteristics correlated to an engine event corresponding to said selected identifying signal, and for providing a diagnostic apparatus fault identifying signal in response to said amplitude variations across said time interval in dependence on the waveshape of said probe signal having characteristics correlated to a faulty condition in said electrostatic signal means.