1.What is a radar level meter? What are its features?
The radar level meter is a type of instrument that emits microwaves through an antenna to the measured medium level, and then calculates the liquid level inside the container based on the time it takes for the microwaves to be emitted and reflected back.
Features:
① No displacement, no transmission components, non-contact measurement, not restricted by temperature, pressure, steam, aerosols or dust. Suitable for the measurement of viscous medium, toxic or non-toxic sanitary medium, and corrosive medium.
②The radar level meter has no measurement blind zone and its accuracy (resolution) can be very high. The measurement error of the liquid level can be as high as 1mm (with special models reaching 0.1mm). Therefore, it can be used as a commercial measurement instrument.
2.What is the measurement principle of the radar level meter?
The radar level meter uses a high-frequency oscillator as the microwave generator. The microwave generated by the generator is led to the radiation antenna through a waveguide and then emitted downward. When the microwave encounters an obstacle, such as the liquid surface, some of it is absorbed and some is reflected back. The liquid level is measured by measuring the relationship between certain parameters of the transmitted wave and the reflected wave from the liquid level.
At present, there are two main types of radar level meters. One type has a fixed emission frequency and measures the travel time of the emitted wave and the reflected wave. Then, through an intelligent signal processor, it calculates the height of the measured liquid level. The relationship between the operating time of this type of radar level gauge and the distance from the liquid level is: t = 2d/c.
c - The speed of electromagnetic wave propagation, c = 300000 km/s;
d - The distance between the measured medium level and the probe, in meters;
t - The time from when the probe emits electromagnetic waves until it receives the reflected electromagnetic waves, S.
The other type measures the frequency difference between the emitted wave and the reflected wave, and converts this frequency difference into an electrical signal that is proportional to the measured liquid level. The emission frequency of this type of liquid level gauge is not a fixed frequency but an amplitude-constant adjustable frequency.
Post time: Dec-03-2025