"A ultrasonic level transmitter use an acoustic pulse emitted from a ultrasonic transducer towards the surface to be measured. This acoustic pulse is then reflected back towards the transducer and the time taken for the pulse to return is accurately measured by a microprocessor-controlled circuitry." . "Qualified" . "ULTRASONIC LEVEL TRANSMITTER" . "ULTRASONIC LEVEL TRANSMITTER" . "RDS1011644" . "A level transmitter that is using ultrasonic sound to continuously monitor the level of a liquid or particulate matter in a tank or vessel." . "u20683" . "2006.06.09" . .