Radar level meter is a kind of microwave level meter, which is an application of microwave (radar) positioning technology. It is transmitted through a device that can transmit energy waves (generally pulse signals), the energy wave is transmitted in the waveguide, the energy wave is reflected when it meets an obstacle, the reflected energy wave is transmitted by the waveguide to the receiving device, and the receiving device receives the reflected signal. The change of level is determined according to the time difference of measuring the energy wave movement process. The microwave signal is processed by an electronic device and finally converted into an electrical signal related to the level. For level and volume monitoring of liquids and slurries in tank liquids, slurries or process containers.

Principle of radar level meter

The radar level meter is sent by the processor and receives the signal reflected from the surface of the material. The processor recognizes the correct echo signal through intelligent software, and uses the equivalent sampling method to accurately obtain the time difference between signal transmission and reception. The time period of the radar signal from transmission to reception is proportional to the distance, that is, the level. The calculation accuracy can reach the millimeter level.

The radar level meter is transmitted by an antenna system and a signal packet with a signal duration of 1ns and a signal period of 278ns. It also conforms to a 3.6MHz signal packet frequency. During the signal cycle, the antenna system operates in the form of a receiver, and the signal cycle less than one billionth of a second must be processed, and the echo image is processed in a time of one second.

The distance D from the surface of the material is proportional to the time travel T of the radar signal:

D = C×T / 2

Where C is the speed of light, since the distance E of the empty tank is known, the object level L is:

L = E - D

By entering empty tank height E (zero scale), full tank height F (full scale) and some other application parameter Settings, the application parameter will automatically adapt the instrument to the measurement environment, corresponding to the 4-20mA output.