摘要 |
An oil monitor assembly (20) comprising a support (22) for removable attachment to an oil reservoir, a first electrode (24, 24') extending from the support (22) for immersion in an oil in the reservoir and a second electrode (28) extending from the support (22) in spaced relationship to the first electrode (24, 24'). An electrical circuit (34) is supported by the support (22) and is in direct electrical contact with the electrodes (24, 24', 28) for measuring the resistance (RRP-29) of the oil over its operational temperature range including the very high resistance of the oil at very cold temperatures to provide a signal in the absence of conducting oil between (29) the first (24, 24') and second (28) electrodes. The electrical circuit (34) includes a degradation circuit (48) for measuring the resistivity of the oil due to contamination and degradation while compensating for changes in resistivity of the oil due to changes in temperature. The temperature-sensitive resistor (RTS-32) is supported by the support (22) and is responsive to oil in the reservoir. The electrical circuit (34) is responsive to the temperature-sensitive resistor (RTS-32) for providing a signal in response to a predetermined temperature sensed by the temperature-sensing resistor (RTS-32).
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