Microwave Barrier Level Measurement

Microwave Barrier Level Measurement

Endress+Hauser’s microwave barrier portfolio (Soliwave) delivers non-contact point level detection and object/flow presence monitoring by transmitting microwaves across a path and evaluating the received signal. Because the energy can pass through non‑metallic windows or vessel walls, sensors can be installed without process intrusion. The principle is robust in dusty, abrasive, or turbulent bulk solid environments, and dedicated versions can also detect bulk movement (flow/no‑flow) via the Doppler effect, which is useful at transfer points and in chutes where optical devices foul.

The core, general‑purpose pair is Soliwave FQR56 (emitter) with FDR56 (transceiver). This compact duo provides reliable min/max limit detection on powders to coarse solids and can even count piece goods. It supports non‑invasive mounting through a transmission window or front‑flush contact installation, with accessories for high temperature and pressure. With the appropriate adapters, the measuring path tolerates up to +450 °C and 21 bar abs, and detection ranges up to 100 m are possible, well suited to large hoppers and long conveyors. Outputs include a relay, a solid‑state relay, and a 4–20 mA signal proportional to received strength, enabling trending of build‑up or fouling. A local indication and 360° rotatable housing simplify commissioning.

For applications that benefit from flow supervision as well as point level, Soliwave FQR57/FDR57 adds integrated bulk‑flow monitoring (flow/no‑flow, trend) alongside limit detection. Typical uses include monitoring of silo discharge, chute/pipe blockage, and material hand‑off points. The platform also supports object detection and deposit/contamination monitoring in filters. In “flow” mode, detection distances depend on the solid but are specified up to about 10 m; the sensing chain is completed with the Nivotester FTR525 control unit. Process adapters extend use up to +450 °C or ~21 bar abs where needed.

Where space is tight or hygienic/cleanable hardware is preferred, the Soliwave FQR16/FDR16 provides an ultra‑compact barrier with simple DC‑PNP outputs. Despite its size, it retains the same non‑contact principle and can be mounted externally through non‑metallic walls; detection range is typically ≤ 20 m. It features permanent self‑diagnosis, IP69 protection, and compliance with EU 1935/2004 for food‑contact applications, making it practical for packaging lines (bag/box counting), small hoppers, and equipment where frequent washdown occurs.

Why microwave barriers? They avoid penetration and moving parts, are largely independent of dust, color, and surface condition, and work where vibrating forks, optics, or capacitive probes struggle, e.g., on wide conveyors, in abrasive streams, or across thick plastic windows. Typical materials include wood chips or flour, cement, ash, gravel, sand, and other dry powders; functions span full/empty alarms, plug‑flow detection, discharge confirmation, material counting/positioning, and trending of deposits to plan cleaning before a shutdown. FLEX selection coverage (Lean and Extended) helps align capability and cost across industries such as mining, building materials, pulp & paper, chemicals, and food.

Vector, your Authorized Endress+Hauser Representative