80 GHz Radar Level Installation: Nozzle, Beam and RFQ Review

An 80 GHz radar level meter offers a narrow beam and small antenna, which can help in vessels with restricted space or internal structures. Those advantages do not remove the need for installation engineering. A poor nozzle, recessed antenna, fill stream, heavy buildup or incorrect reference plane can still produce weak or false echoes. An RFQ should describe the vessel and operating duty well enough to select the exact antenna, process connection, seal, housing and output. The approved drawing and acceptance plan should then carry the same assumptions into installation and commissioning.

Provide complete vessel data

Submit vessel height, diameter, roof, bottom, nozzle dimensions, process connection, maximum and minimum level, overflow point and internal structures. Mark the fill and discharge locations on a plan view.

Describe product dielectric behaviour, temperature, pressure, vapour, foam, dust, buildup and cleaning. Include abnormal states that can be more difficult than normal operation.

Select the mounting position

Place the beam away from the fill stream, ladders, coils, agitators and walls while still observing a representative surface. Check the complete beam envelope, not only the centre line.

For solids, consider the filling cone, discharge funnel and sensor view at low inventory. A narrow beam can measure a local surface that differs from the average inventory profile.

Control nozzle geometry

Compare nozzle bore and length with the exact antenna guidance. Remove internal burrs or weld projections and verify any adapter, reducer or valve through which the radar must radiate.

Position the antenna at the approved projection and orientation. A nominally suitable nozzle can fail if the radiating surface remains deeply recessed or condensation cannot drain.

Verify process and mechanical suitability

Check wetted materials, process seal, pressure rating, temperature limits, hazardous-area marking and environmental enclosure. Include purge or cooling accessories in the certified assembly where required.

Provide a rigid mounting that permits alignment and maintenance. Account for vibration, roof deflection, thermal movement and safe access without exposing personnel to the process.

Specify outputs and protection

Define range, reference plane, blocking distance, response speed, 4–20 mA fault current or digital protocol. State the PLC scaling, alarm setpoints and behaviour on lost echo.

Use independent high-high protection where the risk assessment requires it. The process radar's narrow beam does not make it automatically suitable as the sole overfill safeguard.

Commission against the design basis

Verify installed nozzle, antenna position, alignment and reference dimensions before configuration. Capture echo curves at known levels and during representative filling or agitation where practical.

Test local distance, converted level, PLC value, alarms and faults as one chain. Store drawings, settings, photographs and as-left evidence for future troubleshooting and replacement.

Review installation deviations before release

Create a deviation list for every difference between the approved RFQ drawing and the installed assembly, including nozzle length, adapter, antenna projection, orientation, process seal and cable entry. Classify whether each difference affects beam clearance, blocking distance, pressure integrity, certification or maintenance. Close critical deviations before startup and assign owners and dates to the remainder. This review is especially important when site fabrication occurs after procurement and the transmitter was selected using dimensions that may no longer represent the vessel.

Engineering checklist

Submit vessel and plan-view drawings.
Describe product and abnormal conditions.
Keep the full beam clear of obstructions.
Verify nozzle bore, length and antenna projection.
Specify outputs, faults and protection duties.
Capture echo and loop acceptance records.

Frequently asked questions

Does 80 GHz radar work through any nozzle?

No. Nozzle geometry and antenna position remain critical to signal quality.

Is the narrow beam always better?

It improves geometric separation but may observe a local solids profile rather than average inventory.

What photographs help an RFQ?

Provide the nozzle, tank roof, internal structures, fill point, existing instrument and accessible nameplates.

Need a project-specific review? Send process data, drawings, photographs and acceptance criteria through our contact page.