Measurement System Based on Electrostatic Sensors to Detect Moving Charged Debris with Planar-Isotropic Accuracy

We present a measurement system capable to detect and reconstruct the trajectory of moving charged debris expelled with the exhaust gases or circulating in the lubricating oil of engines, aero-engines, or gas turbines. The measurement technique is based on a circular array of three electrostatic sensors used to estimate the trajectory, the charge, and the velocity of a moving charged particle. We discuss methods to process the information provided by the sensors, combining physical models and the geometrical characteristics of the sensor array, providing a theoretical characterization of the measurement accuracy, which is shown to be not dependent on the direction of the particle motion with respect to the sensor placement. The information obtained with the measurement system can be used to reject false positives when the sensors and the front-end electronics are used in noisy environments.