Atec Panametrics-Olympus-Omniscan-MX - Manual (Page 10)

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10
Eddy Current Array Technology
Eddy current array (ECA) technology
provides the ability to electronically drive
and read several eddy current sensors
positioned side by side in the same probe
assembly. Data acquisition is made possible
through the use of multiplexing, which
avoids mutual inductance between indi-
vidual coils.
The OmniScan ® ECA test configuration
supports 32 sensor coils (up to 64 with an
external multiplexer) working in bridge or
transmit-receive mode. The operating fre-
quency ranges from 20 Hz to 6 MHz with
the option of using multiple frequencies in
the same acquisition.
Benefits of Eddy Current Arrays
Compared to single-channel eddy current
technology, eddy current array technology
provides the following benefits:
• Dramatically reduces inspection time.
• Covers a large area in a single pass.
• Reduces the complexity of mechanical
and robotic scanning systems.
• Provides real-time cartography of the
inspected region, facilitating data
interpretation.
• Is well suited to complex part geometry.
• Improves reliability and probability of
detection (POD).
Eddy Current Array Probes
Olympus NDT manufactures ECA probes
for a wide range of applications. Probes
can be designed to detect a specific type of
flaw or to follow the shape of the part being
inspected. Standard designs are available
to detect defects such as cracks and pitting,
and subsurface defects such as cracks in
multilayer structures, as well as corrosion.
Eddy Current Array Inspection
Eddy current array probes can replace one axis of a two-axis scan and offer greater flexibility
in the eddy current setup.
Transmit-receive probe for corrosion detection down to 6 mm (0.25 in.)
in aluminum
Multiplexing principle between elements. Coils are shown for illustration purposes only.
Probes can be made in different shapes and sizes to follow,
with ease, the contour of the part under inspection.
ECA technology is invaluable in aerospace maintenance
applications
Absolute probe for surface crack detection Transmit-receive probe for surface-crack detection shown
with optional encoder