EoW March 2008

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EuroWire – March 2008 49
english technology news
laserXtens – Zwick’s latest strain
measurement system – has successfully
been used for applications in temperature
chambers where materials are typically
exposed to temperatures from -70 to
+250°C whilst being subjected to tensile
or compressive loads.
Such tests are very important for
the automotive industry where the
measurement of both axial and transverse
strain is often required.
laserXtens measures bi-axial strain without
any specimen contact and without the
need to attach any marks to the specimen.
Part of the specimen surface is illuminated
using the principle of laser speckle
interferometry.
As the specimen is subjected to load, the
reflected speckle pattern is tracked by
two digital cameras, and highly advanced
real-time software algorithms convert this
data directly into strain.
The tests carried out in the temperature
chamber revealed that this measurement
technology was not adversely affected by
the thin layer of frost which had formed
on the specimen. The speckle pattern
was easily detected and could be tracked
during the tests.
Only a window is required in order for
laserXtens to ‘see’ the specimen inside the
temperature chamber so laserXtens offers
significant benefits in terms of its ease
of use. Meeting class 1 of ISO 9513 (class
B2–ASTM E83), the extensometer remains
outside the testing environment and
measures strain up to failure.
Zwick believes that this device will
revolutionise the measurement of strain
on specimens under environmental
conditions.
Zwick GmbH & Co KG – Germany
Fax: +49 7305 10200
Email:
Website:
Extreme temperatures tested the new strain
measurement system
▲
Zwick – covering all the extremes
. . . the most
important source
of information in
the wire and cable
industry . . .