It is a non-contact level transmitter base of time of flight principle of ultrasonic sound signal. It provided reliable level measurement of liquids in tanks. It consists of an ultrasonic transducer integral with microcontroller-based electronics housed in an enclosure. The ultrasonic pulses are emitted from the transducer towards the liquid surface and reflected back to the sensor. This time required between transmitting and receiving pulse is measured by microcontroller based electronics to provide 4-20 mA output.