Radar Level Measurement

Radar Level Measurement

Free-space radar level measurement is a non-contact, continuous technique that measures distance from an antenna to the product surface using microwave time-of-flight. It is used across a broad range of liquids and bulk solids, from simple storage tanks to high-demand process vessels. Because it does not require contact with the media, it is often selected for corrosive, high-temperature, or hygienic services.

The measuring principle emits high-frequency radar pulses from an antenna toward the surface. The pulse reflects where there is a change in relative dielectric constant, and the instrument measures the time-of-flight of the return signal to calculate distance. With tank geometry known, level is computed from that distance. The method is generally unaffected by density and conductivity, and it can be configured for a wide measuring range; certain designs support elevated process temperatures.

Benefits include maintenance-free measurement without wetted moving parts and strong suitability for harsh process conditions such as pressure, temperature extremes, and vapor space variability. Non-contact installation reduces contamination risk and simplifies hygienic implementations. A broad portfolio of antenna styles and frequencies supports optimization for narrow nozzles, long ranges, and challenging reflectivity conditions.

Applications include bulk liquid storage (water, solvents, acids, hydrocarbons), reactors and mixers (when appropriate mounting avoids agitator interference), and tank gauging scenarios requiring high repeatability. In solids, free-space radar is used for powders and granulates where dust and filling noise can be managed through device selection and signal processing. It is also common in water/wastewater and in hygienic vessels for food and life sciences.

Engineering best practice includes selecting antenna type and frequency based on nozzle length, measurement distance, and expected product dielectric properties. Obstructions such as ladders, coils, and internal piping should be addressed through mounting location and echo management. Where foam, heavy condensation, or severe dust clouds are expected, application review should confirm sufficient echo strength and appropriate configuration to maintain stable tracking.

Forberg Smith, an exclusive authorized representative of sales and service for Endress+Hauser.