Radar Level Transmitter

Radar level transmitters are considered one of the most reliable level measurement methods in industrial automation due to their non-contact measurement capabilities and resistance to harsh environmental conditions (dust, steam, pressure).

The working principle is based on sending an electromagnetic wave, its reflection from a surface, and the conversion of this time into distance.

1. Basic Technologies

Radar sensors are divided into two main groups based on how they process signals:

• Pulse Radar: Sends signals in short packets and measures the "time of flight". It consumes less energy and is generally preferred in simple applications.
• FMCW (Frequency Modulated Continuous Wave): It continuously transmits the signal but changes its frequency over time. It measures the frequency difference between the received and transmitted signals. It is much more sensitive and provides more stable results in dusty/turbulent environments.

2. Frequency Selection: Why is it Important?

When choosing a radar transmitter, the most critical decision is frequency:

Frequency: 6 GHz (Low)

Wavelength: Long

Best Application: Liquids with dense vapor, foam, or turbulence.

Frequency: 26 GHz (Mid)

Wavelength: Medium

Best Application: General purpose liquid and solid measurement. Ideal for most standard tanks.

Frequency: 80 GHz (High)

Wavelength: Short

Best Use: Narrow tanks, obstructed areas, and solids like sand/cement. Offers a narrow beam angle, so it won't hit tank walls or obstacles.

3. Points to Consider During Assembly

In radar installations, managing "dead zones" and "reflection" is of vital importance.

1

Determine the mounting location.

Stay away from the walls.

Do not mount the transmitter too close to the tank wall. The signal may bounce off the wall and create false echoes. Ideally, place it 1/3 of the way from the center to the wall.

2

Avoid Inlet Flow

Prevent turbulence.

Do not place the sensor directly above where the material is poured into the tank (fill line). Flowing material will interrupt the signal or give an inaccurate level reading.

3

Check the nozzle size.

The signal should not be blocked.

The nozzle (neck) to which the mounting flange is attached should not be too long. The antenna tip should protrude from inside the nozzle, or the nozzle diameter should not obstruct the antenna's beam angle.

4

Aiming

Especially in solid materials

In bulk materials such as sand, cement, or grain, mounting the radar at an angle using a steering device so that it is perpendicular to the natural flow angle (funnel shape) of the material improves signal quality.