Patent ID: 9222822
Filing Date: 2015-12-29
Classification: G01F,G01N

Abstract:
1. A method of measuring lubricant level and quality using a lubricant sensor that comprises a plurality of electrodes, the method comprising: placing the lubricant sensor into a lubricant; providing a first current, which is AC at a first frequency, (a) between a first electrode and a second electrode of the lubricant sensor and (b) between the first electrode and a third electrode of the lubricant sensor; measuring, at the first current, between the first and second electrodes, and between the first and third electrodes, capacitance parameters used to determine the capacitance between the first and second electrodes and the capacitance between the first and third electrodes; determining the level of the lubricant in which the sensor is placed from the measured capacitance parameters by comparing the capacitance between the first and second electrodes with the capacitance between the first and third electrodes; providing a second current between the first electrode and one of the second and third electrodes, the second current being provided at a different time to the first current and being either: (i) DC; or (ii) AC at a second frequency that is lower than the first frequency; measuring, at the second current and between the first electrode and the one of the second and third electrodes, an impedance or resistance parameter representative of the impedance or resistance between the first electrode and the one of the second and third electrodes; and determining the quality of the lubricant in which the sensor is placed from the measured impedance or resistance parameter.