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A ZwickRoell core competency.

Extensometers are measuring instruments used in materials testing to measure lengths, or extensions of material specimens. Extension measurement is one of ZwickRoell’s core competences. ZwickRoell’s product portfolio includes extensometers with different resolution levels, measuring principles, and measurement travel. 

A distinction is generally made between contact and non-contact measurement of extension, change in width, or strain.

  • Contact measurement can be carried out with a clip-on extensometer, which has at least two probes or knife edges that are placed onto the specimen. As the specimen extends, the distance between the two knife edges changes thereby indicating the specimen extension.
  • Optical extensometers are used for non-contact measurement

The information that follows will provide you with more details on our contact-type and non-contact extensometers and their applications. 

Contact-type extensometers

These extensometers are used for direct extension measurement in tensile tests, flexure tests, and alternating load tests. They all feature a wide measurement range that can be steplessly adjusted to suit the specimen being tested. Clip-on extensometers and extensometers with sensor arms are in direct mechanical contact with the specimen via knife edges positioned at right angles to the gauge length.

Extensometers with sensor arms

  • makroXtens II
  • multiXtens II HP
  • Longstroke extensometer

Digital and analog clip-on extensometers

  • Clip-on extensometer
  • Strain gauge clip-on extensometer
  • digiClip digital clip-on extensometer

Extensometers for compression tests and flexure tests

Non-contact extensometers

The differentiating advantage of extensometers featuring non-contact measurement is that they can be used right up to break without risk of damage, even with specimens that are critical in this respect.

Overview of videoXtens extensometer

Overview of laserXtens extensometer

lightXtens extensometer