基于数字式电容检测的机油品质传感器  

Lubricant Quality Sensor Based on Digital Capacitance Detection

作　　者：刘岳鹏[1] 周磊[1] 郝云择 LIU Yue-peng;ZHOU Lei;HAO Yun-ze(Beijing Institute of Aerospace Testing Technology,Beijing 100074,China)

机构地区：[1]北京航天试验技术研究所

出　　处：《仪表技术与传感器》2020年第1期1-4,8,共5页Instrument Technique and Sensor

摘　　要：针对汽车机油更换周期的问题,设计了一种基于介电常数变化的机油品质检测传感器,通过测量电容值来反映机油的介电常数。传感器采用圆柱型电容结构,并以数字电容芯片AD7745和STC12C5A60S2单片机设计的处理电路实现对电容的快速、准确测量。污油和净油按不同比例混合后获得的样品用于传感器性能测试,并将试验数据与AH2500A型电容电桥的同步测试数据进行对比。结果显示,传感器测量的电容值与标准仪器的结果基本吻合,误差不超过±0.2%,且电容值与污油比例之间具有置信度为0.9897的线性关系。Aiming at the problem of engine lubricant replacement cycle,an lubricant quality detection sensor based on the change of dielectric constant was designed.The sensor gains the dielectric constant by measuring the lubricant capacitance.The capacitance sensor used the cylinder structure.The processing circuit,designed by the digital capacitance chip AD7745 and STC12C5A60S2 micro-controller,realized the capacitance measurement quickly and accurately.The sensor's performance test was carried out by the samples of different blending ratios of dirty lubricant and new lubricant,then the experiment data were compared with the synchronization data of AH2500A capacitance-bridge.The results show the capacitance values measured by the developed sensor are basically consistent with those by the standard instrument,and the errors are within±0.2%.The capacitances have a linear relationship of 0.9897 confidence coefficient with the proportion of the dirty lubricant.

关 键 词：AD7745 单片机 电容 机油品质 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]