Microwave Level Switch

The microwave barrier detects material without touching it, without a probe in the vessel and, if the wall is non-metallic, without a nozzle at all. An emitter sends a microwave beam across the vessel, chute or conveyor to a receiver; when product, whether a rock, a powder, a liquid or a passing object, interrupts the beam, the receiver signal drops and the relay switches. It is indifferent to dust, temperature, humidity, colour and build-up, and there is nothing to wear.

Switches cover distances to 100 m at process conditions to 20 bar and 450 °C. The emitter and receiver mount on opposite sides of the vessel with threaded or flanged connections, or against a PTFE, PP or ceramic window in a metal wall; on plastic and concrete silos and on chutes they can be strapped to the outside. Housings are 316L stainless steel, and high-temperature adapters, mounting straps and adapter flanges are available.

The output is a relay, so integration is simple, and the emitter and receiver are approved for use where the beam passes through hazardous areas.

Applications are overfill protection and empty detection in silos and bunkers, blockage detection in chutes and crushers, level detection in hot or abrasive bulk solids, liquids in plastic vessels, conveyor belt monitoring and object detection in cement, mining, power generation, steel, waste incineration, chemical and logistics.