Extensometers Are a Zwick Core Competence

Extension measurement is one of Zwick’s core competences. Zwick’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.

Which Extensometer Is the Right One?

The demands placed on extensometers vary as widely as the applications for which they are used. The criteria used to determine the most suitable extensometer for a given application or range of applications are also highly varied. The principal factors determining extension measurement requirements are the properties of the material to be tested, the specimen shape and dimensions, and the test standards that have to be complied with (for example, ISO 6892, ISO 527, ISO 10113 etc.). Among other things they define the test sequence, the characteristics to be determined, and with what accuracy, and the environmental conditions, such as the test temperature.

Zwick has a comprehensive selection of extensometers, ranging from an analog clip-on instrument to the fully automatic universal extensometer. Zwick extensometers are designed with the operator in mind. They should be as simple as possible to clamp on the specimen and to operate. Our many years of experience in developing and designing extensometers, manufacturing the instruments in-house from start to finish and performing a wide variety of installations are your guarantee of state-of-the-art extensometry. Zwick’s innovations have placed the company at the cutting edge in many areas.

The key advantages and features of non-contact extensometers

  • The behavior of the specimen is not subjected to any influences caused by knife edges or drag force, therefore it is not damaged and falsification of test results is ruled out.
  • The systems have an extremely long service life.
  • Non-contact extensometers are suitable for specimens that tend to whiplash at specimen break (elastomers, wires, ropes) as well as for notch- and break-sensitive specimens.
  • Required accuracy classes 0.5 and 1 are available.
  • No thermal bridges when using temperature chambers since measurement takes place via a heatable window.
  • Selectable gage length:
  • Application of gage marks with the appropriate separation distance
  • Without gage marks: use of natural surface pattern (for example, the ribs of reinforcing steel)
  • Use of a superficial surface pattern (spray pattern, laser speckle pattern)
  • In addition to results for standard-compliant application tests, non-contact measuring systems provide other useful information such as
  • Biaxial strain: Determination of the transverse strain and reduction in area
  • Measurement of strain distribution
  • Deflection measurement
  • 2D dot matrix measurement: to determine local strains of a flat specimen area in 2 axes (2D)
  • Recording and storing of live images for test re-run with modified measurement ranges
  • Video documentation

A Standard Made in Germany

We manufacture products with maximum care and precision and supply state-of-the-art solutions for research and development to customers from every sector and industry. Our testing machines embody the proverbial quality of "Made in Germany." All of our testing systems comply with the current EC Machinery Directive.

Experience this yourself at our annual exhibition, testXpo, in Ulm.

Dr. Jan Stefan Roell
testXpo tent
  • Made in Germany
  • Safety for the entire testing system
  • Ergonomic operation
  • Flexible and ready for the next generation of technology
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