On bridges, industrial buildings and water networks the steel asset ages under layers of paint and soil. Ultrasonic measurement quantifies the remaining thickness without demolishing anything, and turns a visual inspection into a figure that can be calculated with.
- ✓ Remaining thickness of sections and plate measured through the paint
- ✓ Testing of structural welds with angle probes
- ✓ Verification of tie rod tensioning with the ultrasonic method
- ✓ IP65 instruments for work at height and outdoors
- ✓ Data logger to document the inspection for the client
- ✓ No demolition and no interruption of service
A visual inspection of a steel structure tells you whether there is rust, not how much section is left. It is a decisive distinction: surface rust on an intact section is a maintenance matter, whereas the same rust on a web already reduced by twenty per cent is a structural matter. Without a measurement, the two situations look alike.
The ultrasonic thickness gauge closes this gap: it provides the actual remaining value, point by point, and allows the designer to redo the section check on real numbers instead of a conservative assumption. Since almost every steel structure is painted, the function required is the same as in the previous sectors: the Echo-Echo mode, which measures the metal while excluding the coating.
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On road structures two specific checks are added: the testing of welds at structural nodes, which requires a flaw detector and a qualified operator, and the control of tension in tie rods and large-diameter bolted systems. On buried networks the issue is instead access: measurements are taken where they can be reached, typically at inspection chambers and valve chambers.
The application cases in the sector
| Application case | What is measured |
|---|---|
| Steel structures and heavy steelwork | Remaining section of beams, columns and bracing |
| Bridges, tie rods and road structures | Welded nodes, tension members and tightening of connections |
| Buried tanks and water mains | Remaining thickness at the accessible points of the network |
From the survey to the calculation: what has to be documented
A survey on an existing structure has value only if it can be reconstructed years later by someone who was not there.
- Readings must be tied to coded points, not collected in a list
- The data logger with batching maintains the correspondence between point and value
- The report is generated with DakMaster™, with statistics and charts
- The instrument’s calibration certificate makes the data defensible
On these surveys the periodic calibration of the instrument is not a formality: it is what holds up in the event of a dispute.
Dakota NDT instruments for the sector
| Instrument | When it is the right choice |
|---|---|
| Dakota ZX6-DL | Echo-Echo ThruPaint, IP65 and data logger: surveying a painted structure |
| Dakota CX8-DL | B-Scan and 100,000-reading memory for structured campaigns |
| Dakota CMX1-DL | Measures metal and coating together, useful on protected structures |
| Dakota CMX2-DL | A-Scan and high gain: heavily corroded steel |
| Dakota FX70-DL | Testing of welds at structural nodes, in the field |
| Dakota BT1-DL MiniMax | Verification of tension on tie rods and bolted connections |
Reference standards
- EN 1090 — execution of steel and aluminium structures
- EN 1993 (Eurocode 3) — design of steel structures
- EN ISO 17640 — ultrasonic testing of welded joints
- EN 14127 — ultrasonic thickness measurement
- EN ISO 9712 — qualification of NDT personnel
- EN 15317 — verification of thickness measuring instruments
Frequently asked questions
Yes, with an instrument featuring Echo-Echo mode, which measures between two echoes inside the metal and excludes the coating layer. This is the normal condition in checks on existing structures, where removing the protection would mean having to restore it at every measured point.
It provides the remaining thickness figure, which is one of the inputs to the calculation, not the calculation itself. The section check, the safety assessment and the design conclusions remain the responsibility of the appointed engineer; the instrument serves to replace a conservative assumption with a measured value.
Only where the wall is physically accessible: the probe must rest on the metal, so work is carried out at inspection chambers, valve chambers, exposed lengths or inspection excavations. On buried lengths that cannot be reached, contact ultrasonic measurement is not applicable.
It depends on the standing the survey has to have. For data collection supporting a technical assessment the instrument is used without formal certification; when the outcome feeds into an acceptance test or a standardised NDT inspection, particularly on welds, personnel qualified to EN ISO 9712 are required.
For a survey on an existing structure or a campaign on a water network, write to us indicating the type of structure, the condition of the coating and the purpose of the inspection.
Further information and contacts
Systems division and sensor integration partner : www.roder.it
More information about RODER SRL : about us
Contact for general information : info@roder.it
Contact for information about these products : info@roder.it
The information contained on this web page is provided for information purposes only. Although it has been compiled with the utmost care, it does not constitute a contractual offer or a binding commitment to supply. It may contain transcription, translation or typographical errors. For precise and up-to-date information, please contact our company directly.
Some images on this website have been intentionally generated using Artificial Intelligence (AI). This is because, for many applications and projects, it is not possible to disclose photographs of the installation or of the actual system due to confidentiality agreements, confidentiality clauses and non-disclosure agreements (NDAs).