초록 ▼

The degree of deterioration of lubricating oil used in an internal combustion engine is detected by measuring the lubricating oil dielectric constant with a pair of spaced sensor capacitor electrodes in the lubricating oil. The sensor capacitor is connected to a fixed capacitor to form a voltage div

The degree of deterioration of lubricating oil used in an internal combustion engine is detected by measuring the lubricating oil dielectric constant with a pair of spaced sensor capacitor electrodes in the lubricating oil. The sensor capacitor is connected to a fixed capacitor to form a voltage divider connected across a constant frequency AC voltage source so that a developed voltage across the sensor capacitor corresponds to the lubricating oil dielectric constant. The frequency of the AC voltage is set at a value ranging from 50 KHz to 500 KHz.

대표청구항 ▼

An apparatus for detecting the degree of deterioration of lubricating oil used in an internal combustion engine, comprising: (a) an AC voltage source for generating an AC voltage of a predetermined frequency ranging from about 50 KHz to about 500 KHz; (b) a sensor including a pair of spaced apart el

An apparatus for detecting the degree of deterioration of lubricating oil used in an internal combustion engine, comprising: (a) an AC voltage source for generating an AC voltage of a predetermined frequency ranging from about 50 KHz to about 500 KHz; (b) a sensor including a pair of spaced apart electrodes dipped into the lubricating oil while the oil is in the internal combustion engine, the electrodes and the oil between them forming a sensor capacitor having a capacity that varies as a function of the lubricating oil dielectric constant, circuit means for connecting said sensor capacitor to said AC voltage source and for generating an output having a value corresponding to the lubricating oil dielectric constant; and (c) an indicator connected to be responsive to said output for indicating oil deterioration degree corresponding to the output of said sensor, said indicator being arranged to indicate that the oil deterioration degree is relatively low and high in response to the impedance between the electrodes being respectively relatively high and low, whereby the indicator response is independent of temperature of the oil for oil temperatures above a predetermined level corresponding with operation of the internal combustion engine.