Patent ID: 8378676
Filing Date: 2013-02-19
Classification: G01N

Abstract:
1. A probe device for detecting corrosion in one or more blades of a gas turbine system, the device comprising: (a) a detection head having a shape that conforms to a surface geometry of a filet section of a gas turbine blade, the detection head operable to move along the axial length of the filet section for detecting corrosion pitting; (b) at least one coil device located within the detection head and operable to induce a first magnetic field within an area of the filet in contact with the detection head; (c) a receiver device operable to detect a signal corresponding to a second magnetic field received from the area of the filet exposed to the first magnetic field, wherein the second magnetic field is generated by induced currents in the area by the first magnetic field; and (d) a signal processing device operable to process the detected signal for correlating a corresponding amplitude of the detected signal with the presence of corrosion pitting in the area, wherein the presence of corrosion pitting is determined without any casing disassembly of the gas turbine system; and wherein the receiver device comprises: (i) a first and a second coil device operable to generate a first and a second received signal from the second magnetic field, respectively; (ii) a first and a second band-pass filter device respectively coupled to the first and the second coil device, wherein the first and the second band-pass filter device are operable to filter the first and the second received signal, respectively; and (iii) a differential amplifier device coupled to the first and the second band-pass filter device, wherein the differential amplifier is operable to differentially amplify the filtered first and the filtered second received signal and generate the detected signal.