Thursday, 19 November 2020
Paut: PHASED ARRAY or PAUT NDT ultrasonic inspection by Italsabi

The Phased Array is an Ultrasonic Inspection that can be used as an alternative to Radiographic Controls and it is the most characteristic in Ultrasonic Controls on welds

Unlike the classic non-destructive manual ultrasound tests, the ultrasonic phased array allows, through the electrical manipulation of the probe characteristics, the application of time jumps to the signals sent and received.

This type of non-destructive test uses multi-element probes (arrays) for greater scanning capacity than conventional ultrasound.

The addition of scanners and encoders for data recording provides digital traceability of inspections.

PAUT is therefore replicable and verifiable over time using the dedicated instrument or software.

Some advanced features of PAUT:

  • The creation of the weld groove, resizing algorithms, customized displays, advanced measurement tools
  • The use of Phased Array technology integrated with the use of magnetic scanners allows automatic surface scans.
  • The Phased Array control is mainly used as an ultrasonic control on butt welds, but it can also be used as Corrosion Mapping for residual thickness mapping.

 

PHASED ARRAY ADVANTAGES

  • Electronic (raster) scanning possible without moving the probe Greater control of beam characteristics
  • Possibility of simultaneous inspection with multitude of angles using a probe
  • It can more easily inspect complex geometry or restricted access areas It can replace expensive and dangerous X-ray applications

TOFD (Time of Flyght Diffraction) is a technique that uses a longitudinal wide beam wave.

The acquired TOFD information is used for sizing the defection.

It uses diffraction vs reflection.

The Tofd technique is now widely used in welding control and has now been universally recognized as the technique that allows to obtain the highest POD (probability of detection) of discontinuities.

 

TOFD ADVANTAGES

  • Possibility of investigating a significant volumetric portion of the weld with a simple linear scan parallel to the weld, for discontinuities in any case oriented
  • Significantly reduces inspection times.