Kaidi - 26GHz Radar Level Meter Model 901

I. Product  Overview

This series of radar level meter adopted 26G high frequency radar sensor, the maximum measurement range can reach up to 10 meters. Antenna is optimized further processing, the new fast microprocessors have higher speed and efficiency can be done signal analysis, the instrumentation can be used for reactor, solid silo and very complex measurement environment.

• Principle

Radar level transmitter antenna microwave pulse is narrow, the downward transmission antenna. Microwave exposure to the medium surface is reflected back again by the antenna system receives, sends the signal to the electronic circuit automatically converted into level signals (because the microwave propagation speed, electromagnetic wave to reach the target and the reflected back to the receiver this time is almost instantaneous).

A    Range set

B    Low adjustment

C    High

                  D    Blind area

Datum measurement:  Screw thread bottom or the sealing surface of the flange.

Note: Make sure the radar level meter the highest level cannot enter the measuring blind area (Figure D shown below).

• The characteristics of 26G radar level meter:

Ø  Small antenna size, easy to install; Non-contact radar, no wear, no pollution.

Ø  Almost no corrosion, bubble effect; almost not affected by water vapor in the atmosphere, the temperature and pressure changes.

Ø  Serious dust environment on the high level meter work has little effect.

Ø  A shorter wavelength, the reflection of solid surface inclination is better.

Ø  Beam angle is small, the energy is concentrated, can enhance the ability of echo and to avoid interference.

Ø  The measuring range is smaller, for a measurement will yield good results.

Ø  High signal-to-noise ratio, the level fluctuation state can obtain better performance.

Ø  High frequency, measurement of solid and low dielectric constant of the best choice.

II. Product  Introduction

901 Model 

III. The  Installation Requirements

• Installation guide:

The 901 radar level gauge can be mounted using a threaded connection and flange connection, typically used for the measurement of corrosive liquids in smaller tanks. The instrument is installed at 1/4 or 1/6 of the diameter and the PTFE rod is to be inserted into the measuring tank.

Note: The minimum distance from the tank wall should be 300mm.

Note:  ① datum

    ②The container center or axis of symmetry

• The top conical tank level, can be installed at the top of the tank is intermediate, can guarantee the measurement to the conical bottom.

Typical installation errors：

Ø  Conical tank cannot be installed above the feed port.

Note: outdoor installation should adopt sunshade. 

Ø  The instrument cannot be installed in the arched or domed roof intermediate. In addition to produce indirect echo is also affected by the echoes. Multiple echo can be larger than the real value of signal echo, because through the top can concentrate multiple echo. So cannot be installed in a central location. 

Ø  There are obstacles affecting measurement needed reflection plate.

• Height of nozzle:

Antenna extends into the tank at least 10mm distance.

IV. The Electrical Connection

• The power supply voltage:

(4~20)mA/HART (Two wire system)    The power supply and the output current signal sharing a two core shield cable. The supply voltage range see technical data. For intrinsically safe type must be a safety barrier between the power supply and the instrument.

(4~20)mA/HART (Four wire system)   Separate power supply and the current signal, respectively using a two-core shielded cable. The supply voltage range see technical data.

RS485 / Modbus                                  Power supply and Modbus signal line separated  respectively using a two-core shielded cable, the power supply voltage range see technical data.

• Connection  mode:

Ø  24V two wire wiring diagram as follows:

Ø  6~24V RS485/Modbus wiring diagram as follows:

• Explosion Proof Connection

The intrinsic safety version sensors (Exia IIc T6) use Alu-die casting housing and filling Silicone rubber sealants internal structure aimed to prevent sparks resulted from circuit failure from leaking out. It is applicable for the continuous level measurement of flammable medium under Exia IIc T6.

A safety barrier FBS-2 must be used together with the intrinsic safety instrument. It is an associated device to this product for the power supply of this product. The main specification is intrinsic safety: Exia IIC, voltage of power supply: 24V DC±5%, short-circuit current: 135mA, operating current: 4...20mA.

All cables must be shielded. The max length is 500m for the cable from the barrier to the sensor. Stray capacitor≤0.1μF/Km, stray inductance 1mH/Km. Instrument must be connected to the ground potential. Any unapproved associated device is not allowed to be used.

• Safety  instructions:

Ø  Please observe the local electrical code requirements!

Ø  Please comply with local requirements for personnel health and safety regulations.

All electrical components of instrument operation must be completed by the formal training of professionals.

       Ø  Please check the instrument nameplate to provide product specifications meet your requirements. Please make sure that the power supply voltage and instrument nameplate on the requirements.

• Protection  grade:
  

This instrument meets the protection class IP66/67 requirements, please ensure the waterproof cable sealing head. The following diagram:

How to install to meet the requirements of IP67:

Please make sure that the sealing head is not damaged.

Please make sure that the cable is not damaged.

Please make sure that the cable for use with electrical connection specification.

Cable into the electrical interface before its curved downward, ensure that the water will not flow into the shell, see the①

Tighten the cable seal head, see the②

Please electrical interface will not use blind plug tight, see the③

V. Instrument Commissioning

• There are three kinds of debugging method:

  1) Display / Keyboard  

  2) Host debugging  

  3) HART handheld programmer

• Display / Keyboard:
  

Please debug the instrumentation by four buttons on the display screen. There are three debug menu languages optional. After debugging is generally used only for display, through the glass window can read measured value very clearly.

Display / Keyboard

① Liquid crystal display(LCD) 

② The key

• PC debugging:
  

Connected to PC by HART

①  RS232 interface or USB interface                     

②  Radar level meter

③ HART adapter

④  250 Ω resistor

HART  handheld  programmer:

① HART handheld programmer

②  Radar level meter

③  250 Ωresistor

VI. Structure Size   (Unit: mm)

The outer shell:

• Appearance  size:

901 

• Flange  type:

VII. Technical Parameters

Process Connection             Thread G1½″A / Thread 1½″ NPT /  Flange

Antenna Material                   Stainless Steel  /  PTFE

The outer shell 

The seal between the shell and the shell cover                 Silicone rubber

Casing window                                                                   Polycarbonate

The ground terminal                                                           Stainless steel

The power supply voltage

Two wire system              

  The standard type                   (16 ~ 26) V DC

Intrinsically safe                      (21.6 ~ 26.4) V DC  

Power dissipation                    max 22.5mA / 1W    

Allowable ripple

- <100Hz                                   Uss～100K) Hz                      Uss

Flameproof                            (22.8 ~ 26.4) V DC       2-wire system

(198 ~242)V AC   4-wire system / 110V AC    4-wire system

The cable parameters

Cable entrance / plug           1  M20xl.5 cable entrance

                                             1  blind plug

Terminal                               Conductor cross section 2.5mm² 

Output parameters

The output signal                              (4 ~ 20) mA/RS485

Communication protocol                   HART

Resolution                                        1.6μA

Fault signal                                       Constant current output; 20. 5mA

22mA

3.9mA

The integral time                               (0 ~ 36) s, adjustable

Blind area                                 the ends of the antenna

The maximum distance measurement                 

901                  10 meters   （Liquid type）

Microwave frequency                    26GHz

Communication interface               HART communication protocol

The measurement interval       about 1 second (depending on the parameter settings)

Adjust the time                          about 1 second (depending on the parameter settings)

Display resolution                    1 mm

Working storage and transportation temperature                          (-40～100)

Process temperature (the temperature of the antenna part)            (40～130)℃

Pressure                                     Max.4MPa

Seismic                                       Mechanical vibration l0m/s², (10 ~ 150) Hz 

VIII. Meter  Linearity

901

Emission angle 20° Precision See chart

VIV. Product  Model  Selection

901

License

P    Standard (Non-explosion-proof)

I     Intrinsically safe (Exia IIC T6 Ga)

G    Flameproof (Exd  IIC T6 Gb)

Antenna Type / Material / Temperature

F Sealing horn / PTEE / -40... 130 ℃

Process Connection / Material

G   Thread G1½″ A

N   Thread 1½″ NPT

 A    Flange  DN50 /PP          

 B    Flange  DN80 /PP

C    Flange  DN100 /PP

Y    Special custom

The Outlet  Pipe  Length of the Container

A    Outlet pipe 100mm         

B    Outlet pipe 200mm

The  Electronic Unit

3   (4~20) mA / 24V DC / HART two wire system

4   (4~20) mA / 220V AC / HART four wire system

5    RS485  Modbus / 6~24V/ Four wire system

Outer Covering / Protection  Grade

L    Aluminum / Single chamber / IP67

H    Aluminum / Double chamber / IP67

G   Plastic / Single chamber / IP65

K   Stainless steel / Single chamber / IP67

Cable Line

M    M 20x1.5

N   ½″ NPT

Field Display/The Programmer

A   With

X   Without