ENGINEERING DECISIONS
Engineering logic for this condition
First identify whether the target is a liquid surface beneath foam, the foam layer itself, or a bulk-solids surface behind airborne dust. For liquids, provide dielectric behaviour, conductivity, density, foam thickness, persistence, wetness, agitation and vapour. For solids, provide particle size, bulk density, moisture, dielectric information, dust intensity, repose angle and filling method. These are different measurement models and should not be combined under one generic “difficult level” description.
Map the signal and mechanical environment. Free-space radar behaviour depends on frequency, antenna, beam path, target reflection, nozzle and false echoes. Guided probes interact with coating, bridges and pull forces. Capacitance and point switches depend on material and buildup, while hydrostatic liquid level bypasses the surface but depends on density and pressure reference. Locate sensors away from direct filling impact and moving structures where practical.
Plan commissioning across representative states. Record empty and full references, foam or dust conditions, false-echo mapping, sensitivity and switching logic as applicable. Inspect expected buildup and access for cleaning. Dust-area classification, ingress protection and pressure-temperature capability are configuration-specific and require current evidence. The design should state what happens during a lost echo, buried probe, bridge or failed signal.
Selection inputs and technical route
- Target definition
- Liquid surface, foam interface, point alarm or bulk-solids surface and the required control response.
- Material properties
- Dielectric behaviour, conductivity, density, particle size, moisture, coating and seasonal variation.
- Foam or dust condition
- Thickness, persistence, wetness, intensity, aeration, agitation, filling rate and visibility of the true surface.
- Vessel and mounting
- Nozzle, beam path, probe clearance, internals, filling impact, repose angle and maintenance access.
- Failure and evidence
- Lost-echo or buried-probe response, area classification, component limits and commissioning record.
Applications for engineering review
- Agitated liquid tanks where persistent or intermittent foam sits above the control surface.
- Powder and granular silos where filling creates dense dust, uneven surfaces and changing repose angles.
- Point-level duties where coating, bridging, direct impact and the required fail state are documented.
Limitations and confirmation points
- No technology can be assumed to see through every foam or dust condition; actual material and geometry control the result.
- Heavy buildup, bridging, weak reflection and direct filling impact may require trials, changed mounting or another principle.
APPLICATION RFQ
Information to send for configuration review
- Liquid, foam, point or bulk-solids measurement objective
- Medium, conductivity, dielectric and density
- Particle size, moisture and bulk-density range
- Foam thickness or dust severity across operation
- Vessel, nozzle, internals and mounting drawing
- Filling, agitation, impact and repose-angle conditions
- Coating, bridging, pull force and cleaning access
- Pressure, temperature and environment
- Output, fail state and area classification
- Quantity and required configuration evidence
PRODUCT FAMILIES
Related product categories
APPLICATION FAQ
Frequently asked questions
Can radar always measure the liquid surface through foam?
No. Foam composition, thickness, wetness, bubble structure, frequency, antenna, vessel geometry and dielectric contrast all affect the returned signal. Some foam permits a useful surface echo; other foam attenuates or creates competing reflections. Describe the foam across operating states and provide vessel and nozzle drawings. The proposed arrangement should be reviewed for the actual duty and commissioned while representative foam is present, with a defined lost-echo response.
What bulk-solids data matters when airborne dust is heavy?
Provide particle-size range, minimum and maximum bulk density, moisture, dielectric information if available, dust intensity, filling rate, repose angle, buildup, abrasion and electrostatic concerns. Show filling and discharge locations and any internal structure. Dense dust is only one factor; the uneven surface and weak target may be equally important. Final sensor, antenna or probe selection should use the least favourable credible material and installation condition.
How should a foam or dust level system be commissioned?
Verify the installation against the approved drawing, then observe readings or switch states during representative emptying, filling, agitation, foam and dust conditions. Record reference distances, false-echo mapping, sensitivity, damping and failure behaviour where applicable. Inspect for coating or impact after initial operation. Commissioning can tune an appropriate configuration, but it cannot correct missing mechanical strength, material compatibility, approval scope or a fundamentally blocked measurement path.