Oil Contamination Monitoring Based on Dielectric Constant Measurement

Fault information of machinery equipments is often contained in the process of lubricating oil wearing off. Meanwhile, the dielectric constant of the oil would change accordingly during the process. The principle of online oil contamination monitoring based on dielectric constant measurement is proposed. The measure system is also developed, which includes capacitance sensor, small capacitance detecting circuit and software of monitoring and analysis. Experiments are carried out on lubricating oil polluted by different contamination. The results show that change of lubricating oil´s relative dielectric constant can be detected effectively and properly distinguished using the developed measure system, which can be used to determine the proper oil-replacing period, and to perform fault prediction of the machinery equipments.