| 摘要 |
PURPOSE:To provide a device for detecting a percentage of refrigerant mixed in lubricating oil in a refrigerating device or the like and detecting quantity of oil therein by which the SN of an ultrasonic wave receiving signal is enlarged so as to facilitate discrimination of a signal. CONSTITUTION:Plural notches 16 are provided in the cylindrical part 15a of a sensor holder 15 which pierces the wall of a container where lubricating, oil is contained, and the end plate outer face of which comes into contact with the lubricating oil in the container. An ultrasonic sensor is installed in the sensor holder 15, the reflected wave in the container is increased in the number of times of reflecting noise waves by the notches, so that the attenuation of noise is enlarged. Accordingly, the SN of a received wave is enlarged so as to facilitate discrimination of a signal. |
