ACFM

Eddyfi® TSC Amigo2 and PACE Units

Alternating current field measurement (ACFM) is an electromagnetic technique used for the detection and sizing of surface breaking cracks in metallic components and welds. It combines the advantages of the alternating current potential drop (ACPD) technique and Eddy Current Testing (ECT) in terms of defect sizing without calibration and ability to work without electrical contact respectively.

Details

The Alternating Current Field Measurement – or ACFM – technique was specifically developed to detect and size surface-breaking defects on and around rough welds through several millimetres of non-conductive coating. This is a key advantage because just the costs associated with paint removal, post-MPI re-blasting, and recoating are typically four or five times more expensive than the MPI itself.

While the main failure point in storage tanks is corrosion in the floor plates, from either the top surface or from the underside, the welded sections are also a direct source of damage mechanisms. ACFM is proving itself as the most cost-efficient and trusted method for inspecting storage tank welds to supplement corrosion mapping, successfully detecting large cracks often missed by MPI.

You can’t deny the cost savings of ACFM over MPI; overall, ACFM jobs are typically six times less expensive than their MPI counterparts while providing the added value of a more reliable inspection with data-rich information to pass along to the asset owner.

Benefits

  • Applicable for 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
  • Requires minimal surface preparation and can be applied over paint and other coatings
  • Applicable for under water inspection as well as normal inspection
  • Inspection data can be stored and analysed offline
  • Inspection can be encoded
  • Provides a permanent record of indications
  • Ongoing monitoring capability
  • High temperature capability

Applications

  • Applicable for 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
  • Requires minimal surface preparation and can be applied over paint and other coatings
  • Applicable for under water inspection as well as normal inspection
  • Inspection data can be stored and analysed offline
  • Inspection can be encoded
  • Provides a permanent record of indications
  • Ongoing monitoring capability
  • High temperature capability