Advanced NDT

Alternating current field measurement​

Alternating current field measurement (ACFM) is an electromagnetic technique used for the detection and sizing of surface-breaking cracks in metallic components and welds.

  • Applicable on base material or welds, ferritic or non-ferritic conductive metals
  • Can be used on hot surfaces, underwater, or in irradiated environments
  • Provides both depth and length information
  • Accurate sizing of defects up to 25mm in depth
  • Minimal surface preparation required
  • Can be applied over paint and other coatings
  • Inspection can be encoded

Eddy current array​

Eddy current array (ECA) differs from the standard NDT technique eddy current testing (ET), in that it utilises multiple eddy current coils.

  • Creates a planned view of the component
  • Provides a better resolution in comparison to standard eddy current testing
  • Provides a permanent record

Electromagnetic acoustic transducer

An electromagnetic acoustic transducer (EMAT) is an ultrasonic testing (UT) technique that generates sound in the component being inspected, rather than in the transducer. EMATs are capable of generating all wave modes used in ultrasonic testing, including some modes that are very difficult or impractical with conventional transducers.

  • It is not affected by surface conditions
  • Easier deployment of probes
  • Can be automated
  • It can generate unique wave modes



Guided wave testing

Pi’s parent company, TWI, have been the pioneers of long-range guided wave technology, also known as long-range ultrasonic testing (LRUT), since the mid-1990s. The oil and petrochemical industry's need for a method that could detect corrosion under insulation (CUI) stimulated guided wave research. This research led to the creation of Plant Integrity Ltd and the development of the first commercial guided wave pipe inspection system, Teletest. Guided wave technology is now widely accepted and used to inspect pipes in inaccessible areas such as road and river crossings, power plant tubing, risers, offshore topside pipework, jetty lines, and refinery pipework. Plant Integrity are world experts in guided wave technology, offering services in all aspects of guided waves, including choice and optimisation of technique, limits of detection, and more. Guided wave testing uses controlled excitation of one or more ultrasonic waveforms that travel along the length of the pipe, reflecting from the changes in the pipe. It is typically used to detect corrosion, erosion, and other defects in the pipework.​

  • Provides 100% initial screening coverage
  • Only requires local access to the pipe surface where the transducer array is to be attached
  • Able to inspect inaccessible areas such as clamps and cased or buried pipes
  • It works without the need to remove insulation or coating


3D x-ray microscopy (XRM) is a non-destructive testing (NDT) imaging technique that provides internal, three-dimensional (3D), highly precise information in extraordinary detail. XRM is able to deliver high resolution and contrast in 3D, which reveals previously unseen features and flaws in millimetres down to micrometres. The flexibility of 3D x-ray microscopy means that Pi has been able to provide assistance to clients with projects such as batch scanning of components, confirmation of flaw location and/or issue in parts, assessment of fabrication efficiency between different manufacturing machines, and enhancement of the customer’s own x-ray capacity to enable more detailed assessment and prognosis.

  • Internal 3D information for specimens, samples, equipment and parts, without opening the sample
  • Encompasses a range of length scales, down to the submicron scale, depending on the size of the sample
  • Generates data that can be manipulated to enable quantitative analysis of 3D microstructures, which neither x-ray tomography or micro-focus x-ray can visualise
  • Opportunity to study samples in-situ to examine how a microstructure changes over time, also known as four-dimensional (4D) imaging

Phased-array ultrasonic testing​

Phased array ultrasonic testing (PAUT) utilises multi-element probes, which are individually excited under computer control. By exciting each element in a controlled manner, a focused beam of ultrasound can be generated. Software enables the beam to be steered. Two and three dimensional views can be generated showing the sizes and locations of any flaws detected.

  • It can be used to inspect almost any material and is often used for weld inspections and crack detection
  • It is able to create detailed and accurate cross-sections of a part
  • It is also particularly useful in situations where there is less room for mechanical scanning because it is able to sweep the beam without moving the probe


Thermography uses a camera that contains large numbers of infrared sensors, which can detect and measure small temperature differences. The temperature differences can be interpreted to detect flaws.

  • Can detect sub-surface flaws
  • Can be used on composite materials
  • Data collection system can record temperature changes with time
  • High-speed
  • Portable
  • Non-contact
  • Able to inspect large areas

Time of flight diffraction

Time of flight diffraction (TOFD) is a reliable method of non-destructive ultrasonic testing (UT), used to identify defects in welds. TOFD interprets the time of flight that an ultrasonic pulse takes to find the location of a reflector. It is used on weld overlays, the heat-affected zones of other components, as well as piping, pressure vessels, clad material, storage tanks, and structural steel.

  • Generally only one scan is required to find any defect information within the weld
  • It can locate and measure the size of many different types of defects with incredible precision
  • It has a high degree of repeatability (meaning the growth of any flaws can be tracked over time)

Ultrasonic bond testing

Ultrasonic bond testing (UBT) is a form of ultrasonic testing (UT) used to test bonds, as apposed to welds.

  • Suitable for adhesive bonds
  • Suitable for bonds between welds
  • Can also be used to find defects in composite welds

Ultrasonic corrosion mapping​

Ultrasonic corrosion mapping (UCM) uses a compression probe to measure the thickness of the sample.

  • A robot can be used to map the entire area
  • Ability to measure the differences in remaining thickness

Ultrasonic immersion scanning​

Ultrasonic immersion scanning (UIS), is similar to ultrasonic corrosion mapping (UCM), in that it uses a compression probe to measure the thickness of the test piece.

  • Plant Integrity Ltd has a 7 axis scanner, giving us the capability of scanning complex shapes
  • Our equipment is fixed to a scanner resulting in accurate measuring
  • Uses water for effective coupling