Guided Radar Level Measurement

Guided Radar Level Measurement

Guided radar level measurement supports continuous level measurement in liquids and solids using guided wave radar sensors. A radar pulse is launched down a probe (rod/cable/coax), and reflections from the product surface (and, in many cases, from interfaces) are evaluated to compute level. This guided geometry allows the method to perform well in vessels with challenging internal structures or narrow nozzles where free-space propagation is less predictable.

Benefits include strong signal stability in the presence of vapors, pressure changes, and many foaming conditions because the wave energy is constrained along the probe. Accuracy and repeatability are typically excellent for liquids, and interface measurement (e.g., oil/water layers) is a common strength when the dielectric contrast supports it. Guided radar is also well suited to applications where a defined measurement path is preferred over relying on antenna aiming and echo mapping.

As a contact method, guided radar requires mechanical compatibility with the process. Probe selection and mounting must account for agitation, potential side loading, solids pull forces (for cable probes), and buildup behavior. While guided radar often tolerates moderate coating, heavy buildup or bridging can distort reflections, so probe type, surface finish, and mounting location are key to long-term performance.

Typical applications include chemical and petrochemical tanks, reactors, storage vessels with internal coils or baffles, and separators where interface tracking provides operational value. Hygienic installations in food and beverage can use guided radar where cleanability and repeatable measurement in small nozzles are important. In solids, guided radar is applied when a probe can be accommodated and dust/headspace conditions make non-contact measurements less desirable.

Selection starts with the measurement task (continuous level only vs. level plus interface), then addresses probe construction, length, and mechanical supports. Integration considerations include defining blocking distances, echo handling, and diagnostics strategy so the output remains stable during filling/emptying transients. For safety-related functions, the probe’s mechanical integrity and inspection approach are as important as the electronics configuration.

George E. Booth Co., an exclusive authorized representative of sales and service for Endress+Hauser.