Yes, radar level transmitters are widely used to measure bulk solids such as powder, grain, cement, coal, and pellets. However, their performance depends on several material and installation factors.
1. How Radar Measures Solid Materials
Radar level transmitters emit microwave signals toward the material surface. These signals are reflected back to the antenna, and the device calculates the level based on the time-of-flight of the signal.
For solids, the surface is usually uneven and dynamic, so the reflected signal may vary compared to liquids. Advanced radar devices use signal processing algorithms to ensure stable readings.
2. Suitable Solid Materials
Radar level transmitters work well with:
Grain (wheat, corn, rice)
Powder (cement, flour, lime)
Granules and pellets
Sand, gravel, and minerals
3. Key Challenges When Measuring Solids
a. Dust Environment
Heavy dust during filling or discharge can attenuate the radar signal, especially for lower-frequency devices.
b. Uneven Surface (Angle of Repose)
Bulk solids form a cone-shaped surface, causing signal scattering and potential measurement deviation.
c. Low Dielectric Constant
Some powders (e.g., plastic pellets) have low reflectivity, making signal detection more difficult.
d. Build-up on Antenna
Sticky materials may accumulate on the antenna, affecting signal transmission.
4. Best Radar Type for Solids
Non-contact radar (especially 80GHz) is generally preferred for solid materials because:
Narrow beam angle → better focus, avoids interference from silo walls
Higher frequency → stronger signal reflection from solids
Better performance in dusty conditions
Lower frequency radars (e.g., 6GHz) may be used for very dusty, large silos, but with less precision.
5. Installation Best Practices
To ensure accurate measurement:
Install away from material inlet to avoid heavy dust and falling material
Avoid internal structures (ladders, beams) that may cause false echoes
Use proper mounting angle or aiming devices if needed
Ensure sufficient clearance from silo walls
Radar level transmitters are an excellent solution for measuring solids like powder and grain, especially when using high-frequency non-contact radar (80GHz). With proper selection and installation, they provide reliable, non-contact, and low-maintenance measurement even in challenging silo environments.
Post time: Apr-03-2026