When the lubricant (e.g., oil) is changed on a machine, a switch or a timer is typically manually set. If the operator or maintenance technician forgets to set the timer or switch, or sets such at a later date, the hours since the last lubricant change will be inaccurate and may result in the machine being run using lubricant that is outside the range of recommended useful life. Such may contribute to hardware failure or damage of componentry of the machine by cavitation, corrosion and/or the like.
U.S. Pat. No. 5,604,441 discloses a method and apparatus for detecting the degree of deterioration of a lubricating oil based on a dielectric medium. The apparatus includes a monitoring means for monitoring the capacitance of a sensor to determine the condition of the oil based on a change in sensor capacitance.