External level transducer is an instrument which adopts sonar ranging and micro vibration analysis technology to measure the liquid level from the outside of the container. There is no need to opening holes on the tank wall, as well as the flange, it doesn’t contact the gas and the liquid in the tank. It is a completely non-contact instrument to realize the online installation and maintenance.External level transducer is an instrument which adopts sonar ranging and micro vibration analysis technology to measure the liquid level from the outside of the container. There is no need to opening holes on the tank wall, as well as the flange, it doesn’t contact the gas and the liquid in the tank. It is a completely non-contact instrument to realize the online installation and maintenance.