Does the signal of the reflected wave affect the correct measurement of the radar level meter?

The radar level meter is designed to obtain liquid level information by measuring the time difference between the microwave's emission and the reception of the reflected signal, and using the time difference multiplied by the speed of light. It belongs to the general-purpose radar level meter, which is a measuring instrument based on the time travel principle.

Whether a radar level meter can measure correctly depends on the signal of the reflected wave. If the liquid surface cannot reflect the electromagnetic wave back to the radar antenna in the selected installation location or there are interfering objects within the range of the signal wave reflecting the interference wave to the radar level meter, the radar level meter can not correctly reflect the actual liquid level. Therefore, a reasonable choice of installation location is very important for the radar level meter, in the installation should pay attention to the following points:

                                                                                                                                                                                       (Image source: Internet)

(1) The axis of the radar level meter antenna should be perpendicular to the reflective surface of the liquid level.

(2) Objects such as stirring valves in the tank, adhesions on the tank wall and steps, if within the signal range of the radar level meter, will produce reflective waves that interfere and affect the level measurement. A suitable installation location should be chosen to avoid interference from these factors.

(3) The flare of the radar level meter of the flare type should exceed the inner surface of the mounting hole by a certain distance. The antenna of the rod type liquid level meter should extend out of the mounting hole, and the length of the mounting hole should not be more than 100mm. for the circular or elliptical vessel, it should be installed in the position of 1/2R (R is the radius of the vessel) away from the center, and it should not be installed in the center of the top of the circular or elliptical vessel, or else the radar wave will be reflected in the walls of the vessel, and then converge in the center of the top of the vessel, which will form a very strong interference wave, and it will affect the accurate measurement. The measurement will be affected by the strong interference wave.

(4) For level measurement of vessels with large level fluctuations, a level meter with an attached bypass pipe can be used to minimize the effect of level fluctuations.