kaidi High Temperature Resistant Radar Level Meter

Principle

The general principle of the FM continuous wave radar level gauge is that the radar emits electromagnetic waves on the top of the tank, and the electromagnetic waves are received by the radar after being reflected by the medium. The frequency difference δf between the received signal and the transmitted signal is proportional to the distance R from the surface of the medium: R=C (speed)*δf (frequency difference)/2/K (frequency modulation slope). Because the speed of light C and the frequency modulation slope K are known, the frequency difference δf can be estimated to obtain the distance R from the radar installation position to the material surface, and then through the known total height of the tank, subtract the spatial distance from the radar to the material surface (referred to as Empty height) to get the height of the material level.

Characteristic

1. Millimeter-wave radar, with a measurement accuracy of up to ±1mm, and a minimum blind area of 0.1m.

2. The smaller antenna size satisfies the measurement of more working conditions.

3. A variety of lens antennas, smaller launch angle, more concentrated energy, stronger echo signal, under the same industrial and mining conditions, compared to other radar products have higher reliability.

4. With stronger penetrability, it can be used normally even if there is adhesion and condensation.

5. The dynamic signal range is larger, and the measurement of low dielectric constant medium is more stable.

6. A variety of measurement modes, the radar reaction time in the fast measurement mode is less than 1S.

FWM-21 Product Introducion

Measuring medium: liquid、solid

Measuring range: 0.1m~30m/0.3m~150m

Process connection: flange ≥DN80

Process temperature: -40～120℃/1200℃

Process pressure: -0.1～0.3 MPa 

Antenna size:76mm 

lens antenna Antenna material: PTFE

Accuracy: ±5mm

Protection level: IP67

Center frequency: 80GHz 

Launch angle: 3°

Power source: Two-wire system/DC24V 

Four-wire system/AC220V Six-wire

 system/DC12-24V

Shell: aluminum/plastic/stainless steel

Signal output: Two-wire system/4...20mA/HART 

protocol Four-wire system/4...20mA/HART protocol 

Six-wire system/4...20mA/HART protocol

Installation Requirements

• Installation method 1：Flange mounting
  

When using flange mounting, the minimum distance between the meter and the tank wall should be 200mm.

Note: ①Datum     

         ②Container center or axis of symmetry       

• Installation method 2：Hoisting

(selected according to specific installation conditions）                  

• Installation requirements:

When installing the instrument, avoid installing it above the material inlet, and try to avoid various objects that affect the signal, such as stirring paddles, etc.                        

Under extremely complex working conditions, the instrument  can work normally with the radar installation point as the center and no obstacles in the area with a radius of 20 cm.                                             

• Schematic diagram of installation and takeover

The maximum installation stub height H max depends on the installation stub diameter D and the product launch angle.

Long installation and takeover will affect radar performance. 

Elecitical Connections

• Power Supply

• Connection method

Ø 24V two-wire system wiring diagram is as follows: 

Ø Two-wire and two-chamber wiring diagram shown on the side is as follows:            

Ø Four-wire, two-room wiring diagram：                                                                                     

Ø six-wire wiring diagram of the four-wire system is as follows:

• Safety guidance

Please observe the requirements of the local electrical installation regulations!

Please observe local regulations regarding the health and safety of personnel. All operations on the electrical components of the instrument must be performed by trained professionals.

Please check the nameplate of the instrument to ensure that the product specifications meet your requirements. Make sure that the supply voltage is the same as that on the instrument nameplate.

• Protection level

    This instrument fully meets the requirements of protection grade IP66/67. Please ensure the waterproof performance of the cable gland. As shown below:  How to ensure that the installation meets the requirements of IP67:

    Make sure the seal head is not damaged.

    Make sure the cable is not damaged.

    Make sure that the cable you are using meets the electrical connection specifications.

    Before entering the electrical interface, bend the cable down to ensure that water does not flow into the housing, see ①

    Please tighten the cable gland, see ②

    Please block the unused electrical interface with a blind plug, see ③

Structure Size

• The outer casing size  (unit: mm)

  
  

• Aluminum case:                    

  
  

• Stainless steel case:               

  
  

• Product Size  (unit: mm)                

Meter Linearity

• Beam angle

The beam angle is the beam angle when the radar wave energy density reaches half of its maximum value (3dB width). Microwaves emit signals outside the beam range and can be reflected by interference objects.

The larger the antenna size, the smaller the beam Angle alpha, the less the interference echo will be generated.

For more accurate measurements, avoid installing any internal devices (such as limit switches, temperature sensors, bases, vacuum rings, heating coils, baffles, etc.) within the signal beam range.

Gauge linear

Product Model Selection