Radar Level Meter Operating Principle

 

Low emission energy pulses through very short microwave transmitting and receiving antenna systems. with the speed of light. Running time can be converted to the electronic components of level signals. A special time for a very short extension method ensures stable and accurate measurements.
Even if the condition more complex cases, there is a false echo, with the latest micro-processing technology and deb ing software can accurately analyze the material level echo.

 

 

Input

The antenna receives the reflected microwave pulses and transmitted to the electronic circuit, the microprocessor processes this signal, identify the micro-pulses generated in the material surface echo. Correct echo signal recognition by the intelligent software completed up to millimeter accuracy. Distance D from the material surface and the pulse travel time T is proportional to:

    D=C×T/2
Where C is the speed of light
Because the distance of the empty tank E is known, then the level L is:
    L=E-D

 

Output

By entering the height E (= zero) of the empty tank, full tank height F (= Full Scale) and some applications to set the parameters, application parameters will automatically adapt the instrument to measure the environment. Corresponds to the 4-20mA output.

 

 

Radar Level Meter Design Features

 

◎ NYRD803 of level meter is suitable for continuous non-contact measurements of liquids, Slurry and pellets, pressure variation; the presence of inert gases and volatile situations
◎ Use microwave pulse measurement method, it can be worked normally within the band of frequent industry . For the lower energy beam, can be installed on a variety of metals, non-metallic container or pipe, no harm to humans and the environment.

 

Radar Level Meter Installation requirements

 

Installation description

 

Recommended distance(1) from wall to the outer wall of installed short pipe:

• A distance from the tank wall:1/6 of the tank diameter, min. distance is 200mm
• Not allowed to install above the material feeding silo(4)
• Not allowed to install in the central position(3),in case it is installed in the center, it will cause ma false wave echo,it interrupts wave echo and cause signal loss.
• If the distance between the gauge and wall of the tank cannot be secured, the mediums on tank wall will be adhered causing false wave echo, during the gauge deb ing, the false wave echo has not be saved.

 

Installation inside the tank

• Within then signal wave beam, avoid following material to be installed (1) Limit switch, temperature sensor, etc
• Symmetric position (2) vacuum ring, heating coil, apron, etc.
• If there are (1)(2) interference substances, apply guided wave tube for measurement.

Optimized installation option

• Antenna size: the bigger the antenna size is, the smaller the wave bean angle is, and the interruption wave echo will be weaker.
• Antenna adjustment: adjust antenna to the optimized measuring position.
• Guided wave tube: the guided wave tube is used to avoid interference wave echo.

 

NYRD803 Installation inside the tank

Standard installation:

• Antenna cannot be inclined towards tank wall.
• Horn antenna must be extended outside of the installation short pipe; otherwise the antenna extension pipe has to be used.
• The horn antenna must be adjust to be vertical, do not let the bean point towards tank wall.

 

 

Radar Level Meter Measuring Conditions

Attention

• The measuring range counts from the point where the wave beam touches the bottom of the tank, but under special conditions, if the bottom of the tank is concave or tapered, it is not possible to measure when material level is lower than this point.
• If the medium is low medium electric constant, when it is at the low liquid level, it is visible at the bottom of the tank, now to secure measuring precision, we s est setting the cero position at the low height C position.
• Theoretically, it is possible to reach the tip point of the antenna for measuring, but considering the influence of the corrosion and adherence, the final value of the measuring range must be at the point 100mm way from the tip of the antenna
• For overflow protection, we can define a safe distance added on the blind area.
• The Min. measuring range is related to the antenna.
• Under different concentration conditions, foams can absorb and reflect microwave, but under certain conditions, it is measurable.