Eddy Current Testing (ET)

Eddy Current Testing (ET) is an electromagnetic NDT technique that can detect surface and near-surface defects in conductive materials, as well as accurately measure coating thickness - all without the need to remove existing coatings or surface treatments.

QMS Asset Integrity is NATA-accredited for high-frequency eddy current testing on both coatings (for thickness measurement) and metallic surfaces (for defect detection and characterisation). This dual capability makes ET a valuable, cost-effective inspection tool across a wide range of applications.

ET is particularly useful for inspecting assets where coating removal is impractical or where minimal surface preparation is desired - such as painted structural steel, coated pipework, and operational plant equipment. Our technicians deliver ET services at our facilities and on client sites across Australia.

An alternating current is passed through a coil in the probe, generating an electromagnetic field. When the probe is placed near a conductive material, this field induces circulating eddy currents in the surface. Any discontinuity in the material - such as a crack, corrosion pit, or coating thickness variation - disturbs the eddy current flow, which is detected as a change in the probe impedance.

The instrument displays and records these impedance changes, allowing the technician to identify and characterise defects or measure coating thickness with high accuracy.