Oil state sensor device e.g. for motor vehicle oil derives various parameters of oil condition from output of ultrasonic sensor

摘要

The device has an ultrasonic sensor, and oil state parameters are derived from the senor signal. A temperature sensor measures the temperature of the oil. An oil level sensor detects the oil level. The composition of the oil is determined from the propagation time of the ultrasound signal from the ultrasonic sensor. The composition may be determined in dependence on temperature. The viscosity may be determined based on the sharpness of resonance of the ultrasound signal.