Series UT Ultrasonic Level Transmitters provide reliable, noncontact measurement for liquid level control in tanks and other vessels. Integral electronics generate an ultrasonic pulse which is transmitted through the air space in the tank. The pulse is reflected back to the sensor at the liquid/air interface. From the received echo, the time of flight can be calculated which is directly proportional to the distance of the liquid surface to the sensor. A continuous 4 to 20 mA output signal is generated and updated every half second. Units feature a fully adjustable zero and span, height and distance mode adjustment, lost echo LED indication, and reverse polarity protection.