... .Apply to all kinds of medium 4CE.UL.RoHS Ultrasonic water level meter for water\liquid level measurementUltrasonic level ... dust, smoke, electromagnetic interference, strong corrosion etc. Widely used in chemical, petroleum, metallurgy, coal, building materials, paper making, ... protection industry and so on. Ultrasonic can spread effective in lots of occasion, Such as: storage tank, materials trough, ...