Radar Level Gauge for Automatic Strorage Tank Level Measurement
Radar level gauge is a non-contact level measuring instrument with microwave technolog. No displacement and no transmission parts. Radar level gauge is the perfect choice for non-contact measurement of liquid or material storage tank. Radar level gauges with unique features are an important part of the tank monitoring and control system. Radar level gauge and ultrasonic level transmitter are similar in structure.
- Application：Solid material, Strong dust, easy to crystallize, condensation occasion
- Measuring Range：80 meters
- Process Connection：Thread, Universal Flange
- Process Temperature：-40℃~130℃(Standard type)；-40℃~250℃(High temperature type)
- Process Pressure：-0.1 ~ 0.3 MPa
- Measurement Accuracy： ±15mm
- Protection Grade：IP67
- Frequency Range： 26GHz
Features of SIRD-904 Radar Level Gauge with Parabolic Antenna
Radar Level Gauge with Parabolic Antenna can produce narrow beam width and directivity. When there are many interferences in the tank wall, it can be measured well. It is not affected by false echoes of interferences such as steps.
The parabolic antenna is suitable for liquid and solid applications. Because of the largest diameter, the radar beam is the narrowest and can be used for extremely long measurement distances. The parabola is also the most insensitive antenna type to pollution.
It can be used in applications where antenna condensation is severe, such as asphalt and liquid sulfur.
SIRD-904 Radar Level Gauge with Parabolic Antenna uses a transmission frequency of up to 26GHz. It has:
- The beam angle is small (minimum 5 degrees). The energy is concentrated. It has stronger anti-interference ability. It greatly improves the measurement accuracy and reliability;
- The antenna size is small. It is easy to install and add dust cover and other antenna protection devices;
- The measurement blind area is smaller. Good results can also be obtained for small tank measurement;
- The wavelength is shorter. It is more suitable for the level measurement of small particles.
- It adopts advanced microprocessor and unique EchoDiscovery echo processing technology.
- It adopts pulse working mode. Radar level gauge has very low transmitting power. It can be installed in various metal and non-metal containers, and it has no harm to human body and the environment.
Specifications of SIRD-904 Radar Level Gauge
|Application：||Solid materials, strong dust, easy to crystallize, and condensation|
|Measuring Range：||80 meters|
|Process Connection：||Thread, universal flange|
|Process Temperature：||-40～130℃(standard type) / -40～250℃(high temperature type)|
|Supply：||Two-wire system (DC24V) / Four-wire system (DC24V/AC220V)|
|Signal Output：||Exia ⅡC T6 Ga / Exd IIC T6 Gb|
|Outer Covering：||Aluminum Single Chamber / Aluminum Dual Chamber / Plastic / Stainless Steel Single Chamber|
|Explosion-proof Grade：||4…20mA/HART (two-wire/four-wire) / RS485 Mod bus|
|Antenna Material||stainless steel|
Radar level gauge working principle
Radar level gauge 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.
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).
- A Range set
- B Low adjustment
- C High
- D Blind area
Radar Level Gauge Applications
Radar liquid level can be divided according to the antenna form and can be divided into cone antenna, parabolic antenna, rod antenna.
The cone antenna is suitable for installation on the top of the tank or on the still pipe. Suitable for applications with a large measuring range.
The parabolic antenna is suitable for both liquid and solid measurement applications. Because it has the largest diameter, it has the narrowest radar beam.
The parabolic antenna is also the antenna type that is least sensitive to pollution. Which can be used for extremely long-distance measurement. It can be used in applications with harsh antenna bonding fluids such as asphalt and liquid sulfur.
The rod antenna is small in size, and only the PTFE material is exposed to the atmosphere of the storage tank. Rod antennas are suitable for measurement applications with sanitary requirements or corrosive chemical materials.
For the measurement-level high-precision radar level gauge, the frequency modulated continuous wave type is adopted. Except for fuel oil, asphalt, and other storage tanks with high viscosity and easy condensation. Which use parabolic antennas, other storage tanks use cone antennas.
The inner floating roof tank is designed with a waveguide to achieving accurate measurement of the liquid level of the storage tank. And set up a local indicator on the ground to display the liquid level value. It is convenient for on-site operators to inspect.
Extended reading: Radar Level Meter for Corrosive Liquids
The parabolic antenna is suitable for both liquid and solid applications. As it has the largest diameter it has the most narrow radar beam and can be used for extremely long measuring distances. The parabolic is also the antenna type most insensitive to contamination. It can be used in applications with severe antenna condensation like asphalt and liquid sulphur.
The Rosemount 5900S antennas have a drip-off design which for some versions also include inclined polished PTFE surfaces. Condensation on the antenna is minimized, and the radar signal remains strong. This results in maintenance free operation, high accuracy and reliability.
There is always a suitable antenna for every tank type, tank opening and application:
- Still-pipe array
SIRD-904 Radar Level Gauge with Parabolic Antenna is a cheap alternative to Rosemount 5900S. If you have any technical questions, please contact our sales engineers.
Radar Antenna Types, please refer to:
How a radar level gauge works?
The radar level gauge antenna emits narrow microwave pulses. Downward transmission via the antenna. After the microwave touches the surface of the measured medium, it is reflected back and received by the antenna system again. The signal transmitted to the electronic circuit is automatically converted into a level signal. Because microwaves travel so fast, the time it takes for electromagnetic waves to reach the target and return to the receiver by reflection is almost instantaneous.
How do you calibrate radar type level transmitter?
Set up the guided wave radar level transmitter,
HART communicator, power supply,
and the multimeter as below (see below calibration setup Diagram).
Check the configuration of the lower range value (0% level, 4 mA) and high range value (100% level, 20 mA). Make sure that the inputted data is as per the datasheet.
For example, the lower range value is 10 inch and the high range value is 35 inch (both of it are measured from the bottom of level transmitter probe)
Fill the level transmitter chamber with water up to the 0% level. Read the level measurement in the transmitter LCD (or in the HART communicator). Set this condition as 0% level through HART communicator.
Read the mA output of the transmitter by using a multimeter. Adjust (if any) through the HART communicator so that the output of the transmitter (on the multimeter) is 4 mA.
Fill the level transmitter chamber with water up to the 100% level. Read the level measurement in the transmitter LCD (or in the HART communicator). Set this condition as 100% level through HART communicator.
Read the mA output of the transmitter by using a multimeter. Adjust (if any) through the HART communicator so that the output of the transmitter (on the multimeter) is 20 mA.
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Wu Peng, born in 1980, is a highly respected and accomplished male engineer with extensive experience in the field of automation. With over 20 years of industry experience, Wu has made significant contributions to both academia and engineering projects.
Throughout his career, Wu Peng has participated in numerous national and international engineering projects. Some of his most notable projects include the development of an intelligent control system for oil refineries, the design of a cutting-edge distributed control system for petrochemical plants, and the optimization of control algorithms for natural gas pipelines.