Microwave Barrier Level Measurement

Microwave Barrier Level Measurement

Microwave Barrier Level measurement provides non-contact point-level detection for bulk solids by establishing a microwave signal path between a transmitter and receiver (or transceiver and reflector) and detecting attenuation or interruption when material enters the beam. Because the sensing is based on microwave transmission rather than mechanical contact, it is well-suited to harsh solids environments and can be implemented across chutes, bins, or vessels.

The primary benefit is reliable switching largely independent of material properties such as moisture, conductivity, and many variations in bulk density. With no moving parts in the process, the approach is robust in dusty atmospheres and can tolerate high temperatures when antenna/process interface components are selected appropriately. It is also effective for detecting plugging, blockage, or presence/absence in transfer points where contact switches would wear rapidly.

Engineering constraints include the need for proper alignment and a clear measurement path. Structural obstructions, severe buildup on antenna surfaces, or extreme dust clouds can reduce signal margin if not addressed through mounting, purge options, or sensitivity settings. Mechanical design must consider nozzle geometry, abrasion at the process interface, and sealing for pressure, weather, and hazardous-area requirements where applicable.

Common applications include high-level alarms in silos and hoppers, level detection in chutes and drop legs, and blockage detection in conveyor transfer points, baghouses, and pneumatic conveying lines. It is often selected for solids services where rotating paddles are prone to wear or where contact probes become buried, coated, or damaged. The method supports reliable “present/not present” decisions used for interlocks, alarms, and feed control.

Outputs are typically discrete (relay or transistor) for direct integration into PLC/DCS logic, with self-monitoring features used to detect signal loss or misalignment. Specification focuses on path length, antenna design, mounting geometry, and ensuring adequate signal margin across operating conditions. Proof testing is generally straightforward, and maintenance is limited to inspection and cleaning aligned with the site’s dust and buildup conditions.

Miller Mechanical Specialties, an exclusive authorized representative of sales and service for Endress+Hauser.