Range hood, medium height detection method and control method thereof

The invention discloses an extractor hood, a medium height detection method and a medium height control method. The extractor hood comprises an oil collecting assembly, and the oil collecting assembly comprises an oil cup; the telescopic rod can do telescopic motion in the height direction of the oil cup; the sound wave receiving and transmitting module is used for transmitting sound waves into the oil cup and receiving sound waves returned by a medium in the oil cup, and is arranged on the telescopic rod; the range hood further comprises a processor used for calculating the heights of different media layered in the oil cup according to the number of the sound waves received by the sound wave receiving and transmitting module and the displacement amount of the telescopic rod. Compared with the prior art, the method has the advantages that the gravitational stratification is performed according to different densities of water and ice oil, and the acoustic impedance is different, so that stratification and diff