Design and Noise Control of the Portable Wear Debris Concentration Detector

Wear debris concentration in the lubricant oil contains the information about wear condition of machine. Based on the inductive balance principle and the detection requirement of wear debris, the portable wear debris concentration detector is designed, with accuracy of 10^-6 for metal wear debris concentration in oil. After analyzing the magnetic field of sensor coil, the magnetic uniformity can be improved by reducing the windings height and radius-length ratio. And increasing the Q factor of the coil can improve the amplified ability of the detection circuit for sensor output signal. Aiming to the characteristic that the peak value variation of sensor output signal is very weak, noise model of preamplifier is built and some noise control measures are put forward. The experiments prove that the detector has satisfying accuracy and consistency.