Radar level gauge

Product Overview：
Brown Company's 76-81GHz Radar Level Transmitter is a radar measurement product utilizing the Frequency Modulated Continuous Wave (FMCW) principle. It is widely applicable for measuring distance, material height, volume, weight, and open channel flow in liquids, slurries, and viscous substances. It can also measure solid media such as powders, granules, and bulk materials. Stable measurements are achievable even in dusty or agitated applications. Supports both two-wire and four-wire configurations. The product offers a maximum range of 120m with a minimum dead zone of 0.08m. Its higher operating frequency and shorter wavelength make it particularly suitable for solid applications. Utilizing a lens antenna for transmitting and receiving electromagnetic waves, it delivers unique advantages in high-dust environments and extreme temperatures up to +200°C.

Working Principle：
The general principle of the FM continuous-wave radar level gauge is that the radar emits electromagnetic waves on the top of the tank and the electromagnetic waves are received by the radar after being reflected by the medium.

The frequency difference δf between the received signal and the transmitted signal is proportional to the distance R from the surface of the medium: R=C (speed)*δf (frequency difference)/2/K (frequency modulation slope).

Because the speed of light C and the frequency modulation slope K are known, the frequency difference δf can be estimated to obtain the distance R from the radar installation position to the material surface, and then through the known total height of the tank, subtract the spatial distance from the radar to the material surface (referred to as Empty height) to get the height of the material level.

Product Features：
• Utilizes transmission frequencies up to 76-81GHz, enabling a more compact RF architecture and higher signal-to-noise ratio.
• 5GHz operating bandwidth delivers superior measurement resolution and accuracy, suitable for metrology applications.
• Narrowest 3° antenna beam angle concentrates energy for enhanced interference resistance and reliability.
•Minimized measurement blind zones deliver superior performance even in small tanks.
• Shorter wavelengths enhance reflection characteristics for fine-grained media and inclined surfaces.
• Features high measurement sensitivity, rapid refresh rates, compact antenna size, simple installation, rugged durability, and maintenance-free operation.
• Non-contact measurement eliminates wear and contamination, enabling liquid and solid media detection.
•Utilizes two-wire loop powering technology, transmitting both supply voltage and output signal through a single two-core cable for cost savings.
• Employs advanced microprocessors and unique echo processing technology, suitable for various complex operating conditions. Virtually unaffected by temperature, pressure, water vapor, dust, and other challenging environments.
•  Features extremely low transmission power, enabling installation in various metal and non-metal containers without harm to human health or the environment.
•  The display with buttons allows for convenient setting of the instrument's parameters.

Technical Specifications:

Installation Notes：
When the antenna transmits microwave pulses, it emits within a specific angle. No obstructions should be present within the microwave radiation zone—defined as the area between the lower edge of the threaded connection or flange and the surface of the measured medium. Therefore, installation should avoid internal silo fixtures such as ladders, limit switches, heating equipment, and supports whenever possible. Failure to do so may cause measurement errors. Additionally, ensure the microwave radiation zone does not intersect with the material flow during filling. If necessary, perform “false echo learning” when the silo is empty. During installation, note that the maximum material level must not enter the instrument's measurement blind zone, and a minimum distance must be maintained between the instrument and the silo wall. Install the instrument so the antenna's transmission direction is as perpendicular as possible to the surface of the measured medium. Avoid installation locations subject to vibration.

Recommended Installation Location
Install at a position between 1/4 and 1/3 of the silo diameter, maintaining a minimum horizontal distance of 200mm from the silo wall. Failure to do so may result in erroneous readings. Avoid installation in environments with strong vibrations. For flat-topped or conical tanks, mount the radar level gauge at the exact center of the top to ensure the transmission angle covers the tank bottom.

Common Installation Errors
Ensure no obstructions (e.g., ladders, steps) are within the beam path, as shown below:

Instrument installation must position the antenna beam away from the feed inlet and perpendicular to the material surface, as illustrated below:

Application Scenarios：