Radar Level Site Survey: Data Required Before Model Selection

A site survey is valuable when it records decision-grade evidence rather than a few photographs and a nominal range. Radar selection depends on the required measurement, process envelope, as-built nozzle, beam path, surface behavior, outputs and failure consequence. Missing information is often replaced by assumptions that remain invisible until installation or startup. A structured survey should distinguish measured facts, controlled documents, operator observations and estimates, assign owners to gaps and produce a clear basis for model selection and quotation.

Record the purpose and users

Identify whether the signal supports indication, control, inventory, transfer, alarm or protection and who consumes it. State required units, uncertainty, response and availability. List current problems and the decisions operators make from the value. A replacement project should capture the existing instrument's useful functions and known weaknesses without assuming the same technology or range is correct.

Capture the process envelope

Record medium, dielectric behaviour, density if relevant, temperature, pressure, vapour, foam, condensation, agitation, dust, coating, corrosion and cleaning. Include startup, shutdown, upset and recipe changes. Use ranges with sources, not a single normal value. Mark unknown chemical compatibility or hazardous classification as blocking information where it affects the offered construction.

Measure vessel and reference geometry

Measure height, diameter, roof and bottom profile, nozzle bore and length, adapters, reference plane, zero, empty and maximum levels. Compare drawings with the vessel. State whether volume or mass conversion is required and identify the tank table or density owner. A photograph without dimensions cannot confirm antenna projection or blocking-distance margin.

Map the measurement path

Locate inlets, outlets, ladders, coils, agitators, braces, distributors, floating structures and wall transitions. For solids, document filling cones, discharge funnels and ratholes. For liquids, note turbulence, vortex and foam locations. Mark moving equipment in all positions. Use a dimensioned sketch so the proposed beam or probe path can be reviewed.

Inspect utilities and interfaces

Record supply voltage, loop resistance, cable length, glands, grounding, barriers, surge protection and hazardous requirements. For digital communication, capture protocol, topology, addresses, register expectations, cybersecurity and configuration tools. Identify PLC or DCS tags, scaling, alarms, historian and final actions. This avoids selecting a device that the site cannot power, connect or maintain.

Review access and environment

Photograph the approach, platform, weather exposure, vibration, flooding, temperature, insulation and nearby electrical equipment. Confirm how the instrument will be installed, isolated, inspected and removed safely. Note crane, scaffold, confined-space or shutdown needs. Lifecycle access can change the preferred process connection and antenna even when several models can measure the range.

Assess risk and independent protection

Document maximum fill or discharge rate, remaining response time, overflow or dry-run consequence and current safeguards. Identify whether an independent high-high or low-low function is required. Record common power, logic and mounting dependencies. A process radar should not be assigned a protective duty simply because its displayed value appears stable.

Issue a traceable survey package

Label photographs, dimensions and documents by equipment tag and date. Separate verified values from estimates and list gaps, owner and due date. Include a recommended principle, model constraints, required accessories, approval evidence and acceptance method. Review the package with process, mechanical, control and maintenance representatives before releasing an RFQ.

Engineering checklist

State measurement purpose and users.
Capture normal and abnormal process states.
Measure nozzle and reference geometry.
Map all beam or probe obstructions.
Record power, outputs and system ownership.
Close data gaps before purchase approval.

Frequently asked questions

Are site photographs sufficient for selection?

No. They need dimensions, process data, reference levels and interface information.

What should happen to uncertain data?

Label it as an assumption, assign an owner and define when it must be verified.

Who should approve the survey?

Process, mechanical, instrumentation, control and maintenance stakeholders should confirm their respective boundaries.

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