Simulation of a Capacitive Sensor for Wear Metal Analysis of Industrial OilsP. Venkateswaran, R. Minasamudram, P. Agrawal
Siemens Technology and Services Pvt. Ltd, Bangalore, Karnataka, India
Indian Institute of Technology - Bombay, Mumbai, Maharashtra, India
Lubricant oil is used to ensure proper functioning of industrial machinery such as turbines, gears, bearings and compressors. Oil analysis is used to detect and quantify the presence of wear metals and other contaminants in the lubricant of oil wetted systems, by sensing the change in relative permittivity of the oil as the wear metals pass through capacitor electrodes. Three configurations of capacitor electrodes, parallel plate, interdigitated, and meandering electrodes were studied using COMSOL Multiphysics®. The AC/DC Module of COMSOL was used to evaluate the sensitivity, defined as change in capacitance per wear particle. Simulation results indicate that the change in capacitance increases with increase in particle diameter and the number of particles. Thus the change in capacitance is directly indicative of the wear particle concentration.