What is the working principle of Radar Transmitter?
 

The sensor emits a microwave pulse from its antenna, which travels at the speed of light to the surface of the medium below. A portion of that energy reflects off the medium and returns to the antenna. The time gap between energy emission and receipt is called the “time of flight”, and is proportional to the distance between the medium surface and the sensors measurement location, which is typically located at the bottom of the antenna. The sensor measures the time of flight and translates this value into a continuous 4-20mA signal output that’s proportionate to level within a defined measurement span.

 

When the dielectric constant of the media is ≤ 4, the amplitude of the direct echo from the media may be low and difficult to detect.

A stand pipe installation can be used with liquids with a dielectric constant as low as 1.9.

  
 

Dielectric Constant value of a material indicates its effectiveness in serving as a capacitor to store and electric change, or to a radar sensor, its effectiveness in reflecting RF energy. Radar waves reflect more efficiently with materials of high dielectric constants while lower dielectric constants absorb most of the radar wave.
 

Visit the Flowline website for a list of liquid media and their dielectric constants

The liquid media’s dielectric constant will determine the horn or antenna size and verify the compatibility of the technology.
 

Best for application of:

 Strong signal penetrability with minimal attenuation over distance
 The sensor is intended for chemical storage or process applications in above or below grade tanks of any material
 For challenging process conditions with corrosive media, light surface foam or agitation, higher temperature or pressure, condensation or vapor, and installation in a flange fitting
 Typical applications include bulk storage and process tanks
 
       

Metal tanks

  

Cement tanks

  

Fiberglass tanks

  

Polyethylene tanks

  

Open Air
 

Lmitations: (Factors that could influence performance)

 Air particulates with a high dielectric constant value such as lead or ferroalloy
 Highly dense air particulates that attenuate microwave emission and receipt
 Material build-up on the antenna that degrades microwave emission and receipt
 Mediums with an extremely low dielectric constant value with little reflectivity