KROHNE’s OPTISOUND3010C, 3020C, and 3030C ultrasonic level gauges are noncontact devicesthat provide accurate and reliable measurement +/-.39″ (+/- 10mm) evenwith fluctuating liquid levels, temperature, and vapors. Shortultrasonic pulses ranging from 35 kHz to 70 kHz are emitted by thetransducer to the liquid surface where they are reflected and receivedby the transducer. These pulses travel at the speed of sound, but thetime from the emission to the reception of the signals depends on thelevel in the particular vessel. Using advanced microcomputer technologyand processing software, the OPTISOUND level gauges calculate the exactdistance to the surface. An integrated temperature sensor detects thetemperature in the vessel and compensates the influence of temperatureon the signal running time.