Ultrasonic testing • Thickness gauges • PAUT • TOFD

Industrial ultrasonic testing: thickness gauges, flaw detectors, phased array and TOFD.

Thickness gauges to measure corrosion, conventional flaw detectors, phased array and TOFD systems for welds, with probes, scanners and software. We help you choose the instrument for your component and the procedure you have to meet.

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Quick answer

What is ultrasonic non-destructive testing?

Ultrasonic testing (UT) sends high-frequency sound waves into the material through a probe and reads the echoes reflected by walls and discontinuities. It measures remaining wall thickness from one side and finds cracks, inclusions and lack of fusion in welds, plates and forgings, using conventional UT, phased array or TOFD.

We help you choose the right ultrasonic instrument: quote within 24 hours

How much does an ultrasonic thickness gauge or a phased array cost?

The price varies a lot between a thickness gauge, a flaw detector and a phased array system with TOFD, and probes, scanners and software move it further. Tell us what you need to inspect and we’ll propose the configuration that does the job, without extras you won’t use.

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Thickness gauging, UT, PAUT and TOFD
Technical support in Italy

Ask for a proposal on WhatsApp Call: +39 081 18920194 Or fill in the form →

Ultrasonic Testing

Solution and application configuration.

Here you will find UT, PAUT and TOFD instruments, the criteria for choosing them for your application, and technical-commercial support from DIPITECH.

UT PAUT TOFD instruments for industrial ultrasonic testing

UT, PAUT, TOFD ultrasonics

UT, phased array, TOFD instruments and accessories

Ultrasonic testing is used on welds, wall thickness, laminations, corrosion, forgings and critical plant components, from conventional UT to phased array and TOFD systems.

Portable UT instruments and phased array systems.
Probes, wedges, scanners, encoders and accessories for the application.
Support in choosing the setup according to material, geometry and defect type.

Choosing the instrument

Thickness gauge, flaw detector, phased array or TOFD: which one do you need?

Ultrasonic testing covers very different instruments, from a pocket thickness gauge to a phased array system with an encoded scanner. Knowing which one your inspection needs keeps you from paying for features you won’t use or, the other way around, buying an instrument that can’t meet the procedure.

Comparison of ultrasonic thickness gauge, conventional flaw detector, phased array (PAUT) and TOFD
Instrument	What it measures or finds	Where it is used	Strengths	Limits	When to choose it
Ultrasonic thickness gauge	Remaining wall thickness, measured from one side	Piping, tanks, vessels, hulls, structures	Fast, portable and affordable; dual-element probes also work on corroded surfaces	Measures point by point and does not look for internal flaws	To monitor corrosion and erosion at defined measurement points
Conventional UT flaw detector	Internal discontinuities with a single straight or angle-beam probe	Welds, forgings, castings, plate	Versatile, light, suited to many manual procedures	No image, and the result depends heavily on the operator	For manual inspections to procedure, including field work
Phased array (PAUT)	Flaws and corrosion with electronically steered beams and S-scan and C-scan images	Welds, corrosion maps, complex geometries	Covers several angles in one pass, records the data and documents the inspection	Costs more and needs a dedicated setup and qualification	When you need speed, images and a recorded, repeatable inspection
TOFD	Flaw height, from the signals diffracted at the flaw tips	Medium and thick welds	Sizes flaws accurately and runs fast along long welds	Has dead zones near the surfaces, so it is paired with PAUT	When you need the flaw’s through-wall height, not just its presence

Consider two typical cases. On a steam line that has been in service for years, a thickness gauge with a high-temperature dual-element probe is enough to measure remaining wall at the agreed test points; if you want to see how corrosion is spread along a whole section, you need phased array mapping with an encoded scan, described in our article on corrosion mapping. On a butt weld in a pressure vessel, phased array paired with TOFD finds the discontinuities and measures their height in a single pass, as explained in our phased array guide.

The standards set how the inspection is carried out and what the equipment has to meet. ISO 16810 covers the general principles of ultrasonic testing and ISO 16809 thickness measurement. For welds, ISO 17640 defines techniques and testing levels and ISO 11666 the acceptance levels, while ISO 13588 covers automated phased array and ISO 10863 covers TOFD. For welds on ASME code work, the reference is Section V, Article 4.

Before buying, it is worth reading the guide on criteria for choosing a PAUT and TOFD instrument and the one on the ultrasonic thickness gauge for thickness and corrosion. If you are deciding between ultrasound and X-ray, the comparison is in the article radiography or ultrasonic testing.

Buy or service

Buy the instrument or outsource the inspection to an NDT service company?

It depends on how many inspections you run and who performs them. A company that gauges thickness every week on its own plant, or inspects welds in production, usually finds it more cost-effective to own the instrument and have qualified operators in-house. If you need an inspection only now and then, or a report signed by an independent inspector, an NDT service company is the faster route.

Service companies are in turn the typical customers for phased array and TOFD, because they work across many jobs and must document every inspection. Tell us how many inspections you expect and under which procedure, and we’ll help you work out which route makes sense.

Which setup does your inspection need?

Send us the material, thickness, a photo or drawing of the component and the standard to meet: we’ll recommend the instrument and probes and get back to you within 24 hours.

Thickness gauges, UT, PAUT and TOFD
Technical support in Italy

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Applications

Where industrial ultrasonic testing is used.

WeldsOil & GasEnergyMetal fabricationMaintenanceAsset integrityProductionNDT services

DIPITECH approach

Application first, technology second.

DIPITECH works out the UT, PAUT or TOFD setup with you, based on component geometry, material, accessibility, target defect, procedure and productivity requirements.

What to send us for an evaluation

Material and thickness of the component.
Geometry or joint type, with a photo or drawing.
What you are looking for: weld flaws, laminations or corrosion to map.
Standard or procedure to meet and acceptance level.
Where the inspection happens: workshop, field, surface temperature.
How many inspections you expect and whether you need a recorded report.

Technical criteria

How to choose UT, PAUT and TOFD instruments and probes.

An ultrasonic inspection is configured around the application, because target defect, geometry and material determine the technique, frequency and probe type. These are the parameters DIPITECH evaluates with you.

Conventional UT, PAUT or TOFD

Pulse-echo UT is versatile for thickness gauging and general flaw detection. PAUT (phased array) adds electronic scanning and sectorial imaging, while TOFD performs best in flaw sizing and weld inspection, often alongside PAUT.

Frequency and resolution

Going up in frequency improves resolution on small defects and thin sections, going down gains penetration in thick or attenuating materials. The right frequency is a compromise between the two.

Probes, angles and wedges

Refraction angle, crystal size, number of elements (PAUT) and dedicated wedges depend on geometry and joint type, which makes probe selection the core of the setup.

Defect and criticality

Cracks, lack of fusion, inclusions, laminations and corrosion have different orientation and reflectivity. The target defect is therefore what drives technique, angles and acceptance criteria.

Encoding, encoders and imaging

PAUT and TOFD weld inspections and corrosion maps require encoded acquisition (encoder), data recording and imaging (S-scan, C-scan), for repeatability and a documented report.

Procedure and qualification

Standards, procedures and operator qualification (levels) set calibration requirements, reference blocks and acceptance criteria, so instruments must be chosen in line with the applicable procedure.

To decide when radiography is the better choice, see radiography vs ultrasonic testing. Related technologies are industrial radiography and RVI videoscopy, and the other articles are collected in the NDT technical resources.

Among the technical articles you will find the phased array principle and when moving from UT to PAUT pays off, the criteria for choosing a PAUT and TOFD instrument before you buy, the ultrasonic thickness gauge for wall thickness and corrosion and corrosion mapping with encoded scanning.

Ultrasonics, radiography, magnetic particle and penetrant testing are compared, including on welds, on the page dedicated to non-destructive testing and its methods.

FAQ

Frequently asked questions on industrial ultrasonic testing

What are the ultrasonic non-destructive testing methods?

The main ones are thickness measurement with a gauge, inspection with a conventional single-probe flaw detector, phased array (PAUT), which uses multi-element probes and produces images, and TOFD, which measures flaw height in welds. On top of these come corrosion mapping with an encoded scan and guided-wave techniques for long runs of pipe.

What is an ultrasonic thickness gauge used for?

It measures wall thickness with access from one side only, for example on piping, tanks and vessels in service. Repeating the measurement at the same points over time lets you track corrosion or erosion and decide when to act.

How does an ultrasonic thickness gauge work?

The probe sends a pulse through the material; it reflects off the opposite wall and comes back. The instrument measures the round-trip time and, knowing the sound velocity in the material, converts it into thickness. That is why it has to be calibrated for the material being measured.

How much does an ultrasonic thickness gauge cost?

It depends on the probe type, the required accuracy, measuring through paint, data memory and field ruggedness. A phased array with TOFD is an investment on a different scale, driven by probes, scanners and software. For a thickness gauge, the material, thickness range and surface condition (painted, corroded or hot) are enough for us to quote within 24 hours.

What is the difference between UT, PAUT and TOFD?

Conventional UT works with a single probe in pulse-echo. PAUT uses multi-element probes with electronic scanning and imaging, while TOFD measures the time of flight of signals diffracted from the tips of the discontinuity and is useful for sizing it. On welds, PAUT and TOFD are often used together.

Does ultrasonic testing find cracks?

Yes, UT is particularly effective on planar defects such as cracks and lack of fusion, where it often outperforms radiography. Detectability, however, depends on defect orientation and the chosen technique.

Which probe frequency should I choose?

It depends on material, thickness and the flaw to find. High frequencies give more resolution on small defects and thin sections, while low ones penetrate thick or attenuating materials better.

Is a certified operator required?

As a rule, yes, because UT inspections follow written procedures and require operators qualified by level. DIPITECH’s role is to propose instruments consistent with the applicable procedure and requirements.

How do I request an evaluation?

Message us on WhatsApp or fill in the form with material, thickness, joint type or geometry, target flaw and volumes. If you have a photo or drawing of the component, send it via WhatsApp or email. We’ll reply with the right UT, PAUT or TOFD setup within 24 hours.

Application support

Support with selection, before and after purchase.

From choosing the configuration to after the purchase, DIPITECH remains your technical point of contact in Italy.

Configuration

Technical requirements, probes, accessories, software and documentation your inspection calls for.

After purchase

Technical support in Italy for questions on setup, probes and accessories.

Manufacturer

Contact with the manufacturer for training, service and spare parts.

Contact

Let’s find the right instrument for your inspection.

If you need to buy, evaluate or replace an ultrasonic instrument, a phased array or a TOFD system, DIPITECH Industrial Solution works through the requirement with you, compares the options and quotes the configuration that fits.

Application request

Tell us about the inspection.

We just need the material, thickness, geometry or joint type, the defect to find and how many inspections you expect.