Advanced NDT Services

Phased Array Ultrasonic (PAUT)

Phased Array Ultrasonic (PAUT) systems are advanced ultrasonic methods that are used in situations where conventional NDT can not be applied. PAUT offers the advantage of enhanced imaging of anomalies lying within the inspection area or on the opposite side of the transducer. Weld inspection and crack detection are the most common applications however, it is also a very effective corrosion survey technique.

PAUT differs from manual or automated UT techniques in that transducers are used that contain multiple elements with varying angles and frequencies. Combined with imaging software in the processing unit, dimensions, orientation, and positioning of an anomaly can be accurately determined. In some circumstances, PAUT can be used in-lieu-of radiography or X-ray.

PAUT Scan Plan for component showing inspection coverage.

Top left screen shows position and extent of an anomaly lying at the root of a weld. Other screens provide supporting data.

C-Scan is and automated thickness mapping technique where scan data from a single line is combined with adjacent parallel data sets to from an image of the far side of the inspection surface. Scanning equipment is generally automated, however there are manual systems that can produce similar results without the use of an automated scanner. Imaging is based on color codes assigned to specific thickness ranges yielding a “plan view” of areas varying thickness.

C-Scan image from a scan taken between the 5 O’clock and 8 O’clock position of a pipeline. The lighter yellow pattern represents corrosion channeling caused by standing water in the line.

Alternating Current Field Measurement

The ACFM method induces a current into the part under the probe and measures the associated electromagnetic fields close to the surface. A defect disrupts inspection fields and the information is displayed on the instrument screen. The linear extent of an anomaly are visible on the display which establishes the defect location and length. Through wall extent of the flaw plays an important role in determining structural integrity and this can be calculated from the display data allowing an immediate evaluation of the significance of the indication. ACFM inspection can be performed through paint and coatings, hence it is considered to be a faster and more cost-effective technique than magnetic particle inspection (MPI) where surface cleaning is required.

  • Applicable for ferritic or non-ferritic base material and/or welds
  • Can be used on hot surfaces
  • Provides both depth and length information
  • Accurate sizing of defects up to 25mm in depth
  • Requires minimal surface preparation and can be applied over paint and other coatings
  • Inspection data can be stored and analyzed offline
Pre-job setup in the lab for ACFM field work on a vessel.
ITL’s field hardness equipment is very portable and provides fast, accurate results.

Hardness Testing

Hardness is defined as the resistance to indentation, and it is determined by measuring the permanent depth an indentation. … The Rockwell hardness test method, as defined in ASTM E-18, is the most commonly used hardness test method.

ITL uses Microdur MIC 10 equipment which is capable of reporting hardness values in a variety of conventions. Field use of this equipment is generally easier and of equivalent accuracy to other types of hardness testing methods. In addition, the Microdur equipment converts readings to DIN 50150 and ASTM E 40 in HV (Vickers), HB (Brinell), HRC (Rockwell C), and HRB (Rockwell B). This test method is applicable on all metals, except where the test specimen is such that the test would introduce unacceptable surface variations after the test. For example, circumstances where the test indentations would be so large, as to affect the use or appearance of the part or where the sample size/shape prohibits and effective test.

The following sample characteristics should be considered prior to selecting the hardness testing method to use: Test Material, Sample Size, Thickness, Scale, Shape of sample; round, cylindrical, flat, or irregular.

Material Characteristics

  • Test to check material
  • Test hardenability
  • Test to confirm material treatment process


  • Test to confirm ability to function as designed
  • Wear Resistance
  • Toughness
  • Resistance to impact

Other advanced NDT techniques offered by ITL

Ground Penetrating Radar