Kaidi KD-908 Water level radar Cost-Effective High Frequency Radar Level Meter High Quality Silo Radar Level Meter

1.  Product  Overview

Principle

The radar water level antenna emits extremely narrow microwave pulses that travel at the speed of light, and part of the energy is reflected back when it encounters the surface of the measured medium and is received by the same antenna. The time interval between the transmitted pulse and the received pulse is proportional to the distance from the antenna to the surface of the measuring medium. Due to the extremely high propagation speed of electromagnetic waves, the time interval between the transmitted pulse and the received pulse is very small (nanosecond order) and it is difficult to confirm. The high-frequency radar water level gauge uses a special demodulation technology that can accurately identify the transmitted pulse and the received pulse The distance between the antenna and the surface of the measured medium can be further calculated.

      A    Range set

      B    Low adjustment

      C    High adjustment

      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).

Application characteristics

The radar water level gauge uses a 26GHz transmitting frequency and has: 

Ø Small beam angle, concentrated energy, stronger anti-interference ability, greatly improved measurement accuracy

Ø The antenna is small in size, easy to install, and easy to add dust cover and other antenna protection devices

Ø Lighter weight, about 1KG, easy to install

Ø The maximum measurement range can reach 70 meters, which can cover water level measurement such as large reservoirs

Ø With a variety of output circuit interface and data acquisition system.

Ø The pulse working mode, radar level meter transmit power is very low, no harm to human body and environment.

2. Product  Introduction 

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3. The  Installation Requirements

 Installation Precautions:

Ø Please reserve enough space for installation; Avoid installing in a site with strong vibration;The highest liquid level cannot enter the measurement blind zone;

Ø The instrument must be connected to the ground, and lightning protection measures should be added; sun-shading and rain-proof measures should be taken outside the installation.

Radar and bracket installation diagram (1) 

Radar and bracket installation diagram (2)

Note: When a radar antenna emits microwave pulses, it has a certain emission angle. There should be no obstacles from the bottom of the antenna to the surface of the measured medium and in the area radiated by the microwave beam.

Therefore, avoid shielding facilities as much as possible during installation, and perform "false echo learning" when necessary. 

4. The Electrical Connection  

• The power supply voltage:

• Connection  mode

Ø  24V  two wire wiring diagram as follows:

 Ø  The Modbus-RS485 wiring diagram as follows:

 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 meter fully meets the requirements of protection class IP66/IP67, please ensure the waterproof characteristics of the cable seal.  As shown below:

     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

5. Instrument Commissioning

There are two kinds of debugging method:

1) Display / Button (With split display, you need to debug on the split)

2) Debug through computer software  

Display / Button: 

Debug the meter through the 4 buttons on the display screen. The debugging menu has four languages to choose from. The measured value can be read very clearly through the glass window.

Display / Button    

                                                                                                                    ① Liquid crystal display(LCD)   ② Adjust by button

 PC software debugging:

Connected to PC by HART

①RS232 interface/USB interface      ②  Radar level meter    ③ HART converter    ④  250Ω resistor

 Connected to PC by RS485

①RS232 interface/USB interface     ②Radar level meter     ③RS485 converter

6. Structure Size   (Unit: mm)

The outer shell

Ø Cast aluminum shell

Plastic shell

Product  size:

 Connection bracket size:

With split display, split size：

7. Technical Parameters

Connection mode of the instrument:

 Standard bracket

 With rain cover bracket

 Thread G1½ "A connection

 G1½ " mounting base connection

8.   Meter  Linearity

908

The launch angle depends on the antenna size

-￠76mm                          12°

-￠96mm                          8°

Precision                          See chart

9. Product  Model  Selection

908