Kaidi KD-FMW11 Grain Bin Grain Tanks Grains Silos Level Indicator Radar Level Sensor

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.

FMW-11 Product Introducion

Measuring medium: Liquid

Measuring range: 0.1m~30m

Process connection: Thread G½"A /1 ½"NPT

Flange ≥ DN40

Process temperature: -40～80℃

Process pressure: -0.1～0.3 MPa

Antenna size:32mm lens antenna

Antenna material: PTFE

Accuracy: ±2mm

Protection level: IP67

Center frequency: 80GHz

Launch angle:  8°

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.Threaded installation

  
  

• Installation method 2：Flange mounting

When using flange mounting, the minimumdistance between the meter and the tank wall

should be 200mm.   

Note: ①Datum     

         ②Container center or axis of symmetry        

• Installation method 3：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)                

Technical Parameters

Process Connection                                                           Flange / material PP, PTFE, stainless steel, stainless steel +PTFE flanging

Antenna Material                                                                PTFE

The outer shell                                                                   Cast aluminum / stainless steel / plastic ABS     

The seal between the shell and the shell cover                 Silicone rubber

Casing window                                                                   Polycarbonate

The ground terminal                                                           Stainless steel

Power supply pressure

Cable parameter                           

Cable entrance / plug                        1  M20×l.5 cable entrance

                                                          1  blind plug M20×l.5

Terminal                                            Conductor cross section 2.5mm² 

Output parameters                           

Output signal                                     (4～20) mA /HART

Resolution                                         1mm

Fault signal                                       current output unchanged；20. 5mA；22mA；3.9mA

Integration time                                 (0～20)s, adjustable

Blind zone                                         0.1m/0.2m/0.3m

Maximum measuring distance          30 m

Measurement interval                       1 second (depending on parameter settings)

Adjustment time                                about 1 second (depending on parameter settings)

Working storage and transportation temperature                (-40～80) ℃  

Relative humidity                               ˂ 95%

Pressure                                            Max. 2.5MPa

Shockproof                                        Vibration frequency (10～150) Hz,

                                                          Maximum vibration acceleration l0m/s²

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