The radar level meter works in the mode of transmit-reflect-receive. When the antenna emits an electromagnetic wave that is reflected back through the surface of the object to be measured, it is again received by the antenna. In this process, the time from emission to reception of the electromagnetic wave is proportional to the distance to the liquid surface.
The antenna receives the reflected microwave pulses and transmits them to the electronics, where the microprocessor processes the signals and identifies the echoes generated by the micropulse on the material surface. The correct identification of the echo signal is carried out by the pulse software with an accuracy of up to millimeters. The distance D from the material surface is proportional to the time travel of the pulse T.
D=C×T/2
where C is the speed of light
Since the distance E from the empty tank is known, the level L is
L = E – D
This is set by entering the empty tank height E (=zero), the full tank height F (=full scale), and some application parameters which will automatically adapt the instrument to the measurement environment. Corresponds to 4-20mA output