//High frequency radar level meter ZERO902

High frequency radar level meter ZERO902

(Last Updated On: April 16, 2018)

26GHz  Radar Level  Meter


  1. Product  Overview


This series of radar level meter adopted 26G high frequency radar sensor, the maximum measurement range can reach up to 80 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:
  • Small antenna size, easy to install; Non-contact radar, no wear, no pollution.
  • Almost no corrosion, bubble effect; almost not affected by water vapor in the atmosphere, the temperature and pressure changes.
  • Serious dust environment on the high level meter work has little effect.
  • A shorter wavelength, the reflection of solid surface inclination is better.
  • Beam angle is small, the energy is concentrated, can enhance the ability of echo and to avoid interference.
  • The measuring range is smaller, for a measurement will yield good results.
  • High signal-to-noise ratio, the level fluctuation state can obtain better performance.
  • High frequency, measurement of solid and low dielectric constant of the best choice.
  1. Product Introduction 






Measuring Range:30 meters

Process Connection:Thread, Flange

Medium Temperature:-40℃ ~ 250℃

Process Pressure:-0.1 ~ 4.0 MPa

Accuracy: ± 3mm

Protection Grade:IP67

Frequency Range: 26GHz

Signal Output:4… 20mA/HART (Two-wire / Four)

RS485/ Modbus

Explosion-proof Grade: Exia ⅡC  T6  Ga

Exd ia ⅡC T6 Gb

  1. The Installation Requirements


  • Installation guide:

Be installed in the diameter of the 1/4 or 1/6.

Note: The minimum distance from the tank

wall should be 200mm.

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.

  • A feed antenna to the vertical alignment surface.

If the surface is rough, stack angle must be used

to adjust the angle of cardan flange of the antenna

to the alignment surface.

(Due to the solid surface tilt will cause the echo

attenuation, even Loss of signal.)

  • Typical installation errors
  • Conical tankcannot be installed above the feed port.

Note: outdoor installation should adopt sunshade.

  • Correct
  • Error  rainproof measures
  • 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.
  • Correct
  • Error
  • There are obstacles affecting measurement needed reflection plate.
  • Correct
  • Error
  • Height of nozzle:

Antenna extends into the tank

at least 10mm distance.

  1. The Electrical Connection


  • The power supplyvoltage:


(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 separate drespectively using a two-core shielded cable, the power supply voltage range see technical data.

  • Connection mode:
  • 24V two wire wiring diagram as follows:
  • 220V four wire connection is as below:
  • 24V RS485/Modbus wiring diagram as follows:
  • Safety instructions:
  • Please observe the local electricalcode requirements!
  • 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.

  • 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

  1. Instrument Commissioning
  • There are three kinds of debugging method:
  • Display / Keyboard
  • Host debugging
  • 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

  1. Structure Size(Unit: mm)


  • The outer shell:
  • Appearance size:



  • Flange type:
  1. Technical Parameters

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<lV                                                                                        – (100~100K) Hz                     Uss<l0mV

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



The integral time                               (0 ~ 50) s, adjustable

Blind area the ends of the antenna

The maximum distance measurement  30 meters

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)

902                                                     (-40~250)℃

Pressure Max.4MPa

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


  1. Meter  Linearity


Emission angle                Depending on the size of the antenna

-¢46mm                         18°

-¢76mm                         12°

-¢96mm                          8°

-¢121mm                        6°

Precision                          See chart

  1. Product Model Selection
  • 902


P    Standard (Non-explosion-proof)

I     Intrinsically safe (Exia IIC T6 Ga)

G    Intrinsically safe type, Flameproof (Exd (ia) IIC T6 Gb)

Process Connection / Material

G   Thread G1½″A / Stainless Steel 304

N   Thread 1½″ NPT / Stainless Steel 304

A    Flange DN50 / Stainless Steel 304

B    Flange DN80 / Stainless Steel 304

C    Flange DN100 / Stainless Steel 304

Y    Special Custom

Antenna Type / Material

A   Horn Antenna Φ46mm / Stainless Steel 316L

B   Horn Antenna Φ76mm / Stainless Steel 316L

C   Horn Antenna Φ96mm / Stainless Steel 316L

Y    Special Custom

Seal Up / Process Temperature

V   Viton / (-40~150) ℃

K   Kalrez / (-40~250) ℃

The  Electronic Unit

2   (4~20) mA / 24V DC / Two wire system

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

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

5   RS485 / Modbus

Shell / Protection Grade  

L    Aluminum / IP67

G   Plastic/ IP65

Cable Line

M    M 20×1.5

N   ½″ NPT

Field Display/The Programmer

A   Belt

X   Without


By | 2018-04-16T06:14:00+00:00 April 16th, 2018|Level meter|Comments Off on High frequency radar level meter ZERO902

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