应用平行极板式电容传感器检测润滑油品质的研究

Study on Detection Method of Lubricating Oil Quality by Parallel Electrode Capacitance Sensor

分析和探讨了润滑油介电常数变化的微观原因,并基于介电常数测量原理,以实现润滑油质量的现场快速检测为目的,考虑灵敏度、信噪比、击穿电压等参数要求,设计了平行极板式电容传感器。采用谐振法对不同使用期的油样进行了测试实验,其中重复性测试数据的最大偏差为4.8%。应用计及边缘效应影响的计算公式对数据进行了处理,结果表明该传感器能在不改变机器内部油路结构的情况下快速有效地检测油液介电常数的变化,为科学判断润滑油使用状况提供依据。

The microcosmic cause of dielectric constant changes is analyzed. Based on this principle of dielectric constant measurement, in order to measure lubricating oil quality, considering SNR and other factors, the parallel electrode capacitance sensor was designed. The testing experiments were carried out on the lubricating oil sample in different application period with resonance method. The windage of maximun deviation is 4.8%. The data is processed by using formula which takes axial edge effect into account. The results show that changes of lubricating oil＇s dielectric constant can be detected effectively without changing the oil tube in the machine, which can provide reference for estimating the state of lubricating oil.