Español 
pусский 
العربية 
Português 
Related Products
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
908F
Application: sewers, manholes, and waterways
Measuring Range: 0~30 meters
Process Connection: Gantry frame / locking flange from DN 80/ 3"
Temperature: -40℃ ~ 80℃
Process Pressure: -0.1～0.3MPa
Precision: ± 5mm
Frequency : 26GHz
Protection Grade: IP68
Power Supply: DC(6~24VDC/AC220V) / 4-wire
DC 24V / 2-wire
The Signal output: Modbus-RS485
4~20mA / Hart (2-wire / 4-wire)
The Scene Display: Optional
Outer Covering: PP
3. The Installation Requirements
Installation Precautions:
The 908F is generally used for installation in water wells, mainly connected by a gantry frame or locking flange. Connected with a gantry frame, it can be installed on the side wall and top of the water well; When installed on the top, lifting is also used, as shown in the following figure.
Precautions during installation:
4. The Electrical Connection
The power supply voltage:
| (4~20)mA/HART (Two wire system) | The power supply and output current signal share a two core shielded cable. Please refer to the technical data for the specific power supply voltage range. For intrinsically safe types, a safety barrier must be added between the power supply and the instrument. |
| (4~20)mA/HART (Four wire system) | The power supply and current signal are separated and each uses a two core shielded cable. Please refer to the technical data for the specific power supply voltage range. |
| Modbus - RS485 | Power supply and Modbus signal lines separated respectively using a shielded cable, the power supply voltage range of see technical data. |
Connection method
The 24VDC two wire system wiring diagram is as follows:
The 6-24VDC four wire system wiring diagram is 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 instrument fully meets the requirements of protection level IP68, please ensure the waterproofing of the cable sealing head. As shown below:
Please ensure that the sealing head is not damaged.
Please ensure that the cable is not damaged.
Please ensure that the cables used comply with the electrical connection specifications.
Before entering the electrical interface, bend the cable downwards to ensure that water does not flow into the casing.
Please tighten the cable sealing head.
Please plug unused electrical interfaces tightly with blind plugs.
5. Instrument Commissioning
There are three kinds of debugging method:
① Split display/buttons (if equipped with split display, debugging needs to be carried out on the split, and the connection method is shown in the attached connection diagram)
② Upper computer software debugging
③ HART handheld programmer (4-20mA output)
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
Programming of a HART handheld programmer
① HART handheld programmer ② Radar water level gauge ③250 Ω resistor
6. Structure Size (Unit: mm)
Product size:
Gantry frame size:
7. Technical Parameters
General data | |
| The outer shell material | PP fully sealed |
| Process connection | gantry frame/ locking flange starting from DN 80/3 " |
The power supply | |
Two wire system | DC 24V / 4~20mA / Power dissipation 0.75W |
Four wire system | (6～24) V DC / Modbus-RS485 / Power dissipation 90mW |
Allowable ripple | - <100Hz Uss<lV - (100～100K) Hz Uss<l0mV |
Output parameters | |
The output signal | (4 ~ 20) mA / Modbus-RS485 |
Communication protocol | Modbus / HART |
Resolution | 1.6μA |
Fault signal | Constant current output; 20. 5mA；22mA；3.9mA |
The integral time | (0 ~ 36) s, adjustable |
| Characteristic Parameters | |
| Blind area | the ends of the antenna |
Maximum distance measuremen | 30 meters |
Microwave frequency | 26GHz |
The measurement interval | about 1 second (depending on the parameter settings) |
Adjust the time | about 1 second (depending on the parameter settings) |
Display resolution | 1mm |
Working storage and transportation temperature | (-40～80) ℃ |
Process temperature (the temperature of the antenna part) | (-20～100)℃ |
| Relative humidity | ˂ 95% |
Pressure | Normal atmospheric pressure |
Seismic | Vibration frequency (10～150) Hz, maximum vibration acceleration l0m/s² |
8. Meter Linearity
908F
The launch angle depends on the antenna size
-￠76mm 12°
Precision See chart
9. Product Model Selection
908F
License |
P standard (non-explosion-proof) |
Process connection / materials |
A gantry frame B locking flange from DN 80/3 " Y Special custom |
Seal / process temperature |
V Viton/（-40~80） ℃ |
The electronic unit |
V Modbus-RS485 / ( 6~24V )DC 4-wire system W （4~20）mA / 24V DC / HART 2-wire system |
Shell / protection class |
G Plastic Single chamber /IP68 |
Cable line |
H aviation connector, can be equipped with leads I Lead length 5 meters J lead length 10 meters K Special Customization |
The scene shows / programming |
A With X Without |
We are here to help you! If you close the chatbox, you will automatically receive a response from us via email. Please be sure to leave your contact details so that we can better assist
