The 2-wire Radar Level Transmitter, RD780, has a frequency of 76–81 GHz with a narrow beam angle up to 30m and uses Frequency Modulated Continuous Wave (FMCW) technology, which has greater accuracy for liquid level measurement. The continuous wave is reflected off the surface of the target medium to be received again by the same antenna. The signal is then transmitted to the electronics with a time lapse.

The duration between signal emission and reception by the antenna is directly proportional to the distance between the surface of the target liquid and the reference point on the antenna.

This time lapse is difficult to measure accurately because the electromagnetic waves travel at such high speeds. Radar level transmitters address this problem by using a demodulation technique that precisely detects the time delay between pulse emission and reception. This allows for highly accurate level measurements.