An ultrasonic level meter is a non-contact instrument used to measure the level of liquids or solids inside a tank or silo. It works by emitting an ultrasonic pulse downward from a transducer; the pulse reflects off the material's surface and returns to the sensor. The meter then calculates the distance based on the round-trip time of the sound wave using the formula S = C × T / 2. It features advanced microprocessor control, built-in temperature compensation, and simple calibration. Because it is non-contact and has no moving parts, it requires low maintenance and is suitable for both liquids and solids. However, its accuracy can be affected by a blind zone near the sensor, as well as by foam, vapor, dust, or turbulence.