1. Working Principle

 

1.1 Measuring Principle

Guided wave radar level meter are a kind of measuring instrument based on the time travel , radar wave are travelling as light speed , the travel time can be transformed into level signal by the electronic parts . The detector can send the HF pulse and spread along cable , when the pulse meet the level surface , it will be reflected and received by the receptor inside the instruments , then the receptor will transform the distance signal into level signal.

 Input

The reflected impulse signal is transmitted along the problem to the circuit of the gauge .

The microwave processor processes this signal , and recognizes the wave echo of the microwave impulse from the material surface .

The correct wave echo signal is recognized by the intelligent software , the distance from the material surface D is proportional to the flying time of the impulse T:

   D=C×T/2

  C is the velocity of light .

   As the distance of the empty tank E is known , so

   L=E-D

 

Output    

   By inputting empty tank height E(zero point) , full tank height F(full measuring range) and some application parameter are set . With the application parameters , the transmitter will automatically adapt itself to the measuring environment, corresponding 4-20mA output .

Measuring range

 

H----Measuring range

L----Empty height 

B----Blind area at the top 

E----the minimum distance from the probe to the tank wall

The blind area at top is the minimum distance from the highest position of the material level to the measuring reference point     (the thread of the flange).

    The blind area at bottom is the distance around the bottom of the probe which cannot be measured exactly.

The effective distance is the distance from the top blind area and bottom blind area.

   Caution: Transmitter can supply reliable level measurement only when the level is among the top

blind area and bottom blind area.

 

  1. Product Introduction

 

 

 

 

 

FRL-SERIES Guided wave radar level transmitter

     

Model

FRL-701

FRL -801

FRL -901

Measuring range

30M

6M

6M

Process connection

Thread /flange

Thread /flange

Thread /flange

Process Temperature

-40-250℃

-40-250℃

-40-250℃

Process Temperature

-1.0-40bar

-1.0-40bar

-1.0-40bar

Accuracy

±1mm

±1mm

±1mm

Frequency Range

100MHZ-1.8GHZ

100MHZ-1.8GHZ

100MHZ-1.8GHZ

Explosion proof/ingress protection

EXiaIICT6/IP68

EXiaIICT6/IP68

EXiaIICT6/IP68

Signal Output

4…20mA/HART(two wires )

4…20mA/HART(two wires )

4…20mA/HART(two wires )

 

 

 

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