Guided Wave Electro Magnetic Acoustic Transducer (EMAT) Inspections

Guided Wave

ELECTRO MAGNETIC ACOUSTIC TRANSDUCER (EMAT) INSPECTIONS

IRISNDT uses EMAT guided waves to inspect piping for metal loss. More specifically, we use the technique to inspect inaccessible areas such as that under pipe supports. The guided waves can travel in the circumferential or axial direction and are sensitive to thickness changes (corrosion losses) on entire volumes of pipe (equally sensitive to internal and external wall loss). To assess the location and extent of corrosion damage, IRISNDT uses EMAT guided wave ultrasonic wave arrival time (velocity change) and amplitude information.

IRISNDT APPLIES EMAT GUIDED WAVES FOR:

Detecting touch/contact point corrosion
Detecting corrosion under supports
Identifying soil to air interface corrosion
Detecting corrosion, erosion and cracking in ground piping
Detecting corrosion, erosion and flaws in furnace tubes

ADVANTAGES

This dry and non-contact method does not require an acoustic couplant
It allows up to 2.5 mm (0.1 inch) lift-off
Allows coverage of up to 1 meter (3.3 feet) with short range guided wave
Allows for the inspection of physically inaccessible areas
Allows real time analysis and storage of inspection data
The data is represented in A, B and C-scans)
The high frequency guided wave results in better accuracy and resolution than the low frequency guided wave (long range guided waves)
Applicable to pipe diameters greater than 50 mm (2 inch) using axial guided waves, and pipe diameters ranging from 150 mm (6 inch) to 600 mm (24 inch) using circumferential guided waves.
Can be used at up to 200 °C (392 °F)