Free space Radar

This non contact radar technology has two different versions:

• Pulse generated
• Frequency modulated continuous wave (FMCW)

What is Pulse generated Radar technology?
An electromagnetic wave between 1 and 100 GHz is sent from the antenna toward the process surface in search of a change in impedance, which will reflect the signal back to the transmitter.

The dielectric of the product is important when selecting a radar unit because the greater the dielectric, the greater the change in impedance and the stronger the reflection.

The size of the radar horn, the dielectric of the product, and the condition of the process surface (calm or agitated) determine the maximum distance from the device to the process surface.

Free space radar sends an electronic signal that either bounces off the surface or shifts its frequency to determine level

What is FMCM?
The FMCW radar versions send out a continuous radar signal, and the frequency shifts as the distance to the process changes.
Because FMCW is a continuous wave, it never loses touch with the material, making it better for agitated vessels.


Advantages:

• It can work in vaccum.
• Relatively unaffected by environmental conditions such as different gases or vapours between the transmitting device and the process surface.
• largely impervious to variations in process temperature or pressure.

Disadvantage:

• Condensation is typically a high dielectric liquid, and the radar signal cannot penetrate this material, resulting in increased “noise” in the launch area of the signal.
• Foam is very difficult to quantify for radar as it is not readily distinguishable from the process surface