KROHNE’s OPTISOUND 3010C, 3020C, and 3030C ultrasonic level gauges are noncontact devices that provide accurate and reliable measurement +/-.39” (+/- 10mm) even with fluctuating liquid levels, temperature, and vapors. Short ultrasonic pulses ranging from 35 kHz to 70 kHz are emitted by the transducer to the liquid surface where they are reflected and received by the transducer. These pulses travel at the speed of sound, but the time from the emission to the reception of the signals depends on the level in the particular vessel. Using advanced microcomputer technology and processing software, the OPTISOUND level gauges calculate the exact distance to the surface. An integrated temperature sensor detects the temperature in the vessel and compensates the influence of temperature on the signal running time.