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Alternating Current Field Measurement (ACFM)

Using Advance Technologies to Inspect Cracks and Welded Joints

What is alternating current field measurement?

Alternating current field measurement (ACFM) is a nondestructive evaluation method first used in the oil and gas industry in 1991 to inspect welded joints on off-shore platforms and processing plants. ACFM combines the advantages of the alternating current potential drop (ACPD) and eddy current testing methods, resulting in a specialized testing technique that measures sizes without calibration, and magnetic fields above a specimen surface instead of the surface voltages. This makes ACFM a safe and reliable technique for detecting and sizing cracks in metallic components, even when those components are coated with paint or other materials.

What are the advantages of alternating current field measurement?

Conducting plant and facility inspections using rope access technology offers a number of important advantages.

Does not require cleaning to bright metal - ACFM can examine surfaces through non-conductive coating and scale with thicknesses of 5mm or greater.

Crack depth measurement - In addition to measuring crack length, ACFM can measure crack depth with a + 20% accuracy.

High temperature applications - Specialized, high-temperature ACFM probes can conduct online measurements of systems and components that operate at temperatures up to 500°C.

Supports record retention efforts - ACFM provides a permanent electronic record of inspection results to be stored, replayed, reviewed and reproduced as necessary.

TÜV SÜD’s technicians are fully trained and independently certified to conduct ACFM and all other nondestructive evaluation techniques. TÜV SÜD’s ACFM equipment and technique approvals are approved by ABS, Lloyds, DNV and OCB Germanisher Lloyd.

Why use TÜV SÜD America for your alternating current field measurement requirements?

TÜV SÜD America, Chemical, Oil and Gas is a leading provider of advanced nondestructive testing services, and pioneered the use of long-range guided wave ultrasonics in inspection services. Our mechanical integrity program is recognized as the standard in the petrochemical industry. TÜV SÜD laboratories and testing facilities can perform quality inspections on almost any form of ferrous material, component or product assembly. Finally, our inspectors are certified to the American Society of Nondestructive Testing (ASNT) Level III and Level II requirements.

TÜV SÜD America, Chemical, Oil and Gas has been synonymous with quality inspection services in the energy and chemical industries for more than 30 years. We’re part of the global network of TÜV SÜD AG, and have access to a complete range of product testing, certification and audit services. From unbundled risk evaluations to management systems and product testing, we deliver what other inspection companies cannot.


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