Strain measurement for materials testing is Epsilon's sole business

Over forty years of experience have gone into the development of Epsilon's products. At their facility in Jackson, Wyoming, they design and build extensometers for testing around the world.

Extensometers are available for testing almost all engineering materials, including metals, composites, plastics, ceramics, elastomers, geomaterials (e.g. rock, concrete, and asphalt), and biomaterials including bone.

There are models for tiny and delicate samples, including relatively fine wire, up to massive metal samples and large rock cores. The huge variety of models covers nearly every type of test as well, including: tensile, compression, bend, fracture mechanics, and cyclic strain controlled tests like low cycle fatigue. Many of our extensometers are capable of relatively high frequency operation as well.

Some key aspects of Epsilon:

  • World’s largest extensometer manufacturer
  • Unrivaled quality

  • Responsive – talk to our experts anytime

  • Broadest product line anywhere

  • Expertise – in both testing and extensometers

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Epsilon's Technology Product Line



  • Optical and laser extensometer models for non-contacting axial tension and compression
  • Optical models may also be used in strain control and for cyclic testing at >100 Hz
  • One system for many different tests, measuring ranges, and gauge lengths

Fracture Mechanics clip-on


  • 3 models cover a broad range of gauge lengths, measuring ranges and temperatures
  • For fracture mechanics and fatigue crack growth tests in compliance with various standards
  • Temperatures from -270 to +1600 °C

High Temp Trans & Dia


  • 1 un-cooled unit for use inside chambers to 700 °C (1300 °F)
  • 1 model for use with split furnaces and induction heating, to 1000 °C

Bolt Proof & Lap Shear


  • Specialized extensometers for

    • Bolt proof testing and elongation measurement
    • Elongation of rebar splice assemblies
    • Lap shear, sandwich core shear, and rigid cellular plastic shear
    • Testing while submerged in liquids

Interface Electronics


  • For customers who do not have signal conditioning as part of their test controls
  • 1 analog and 4 digital versions for strain gaged sensors



  • 7 models in this group cover tension, compression and cyclic testing
  • Huge variety of gauge lengths and measuring ranges
  • Temperatures from -270 to +200 °C



  • Widely used for 3 and 4 point bending tests, compression tests and general deflection measurement

Rock, Concrete & Asphalt


  • 7 models cover axial, circumferential and diametral testing on aggregate material



  • Examples of modified standard extensometers and application-specific extensometers



  • 2 digital models. Choice of 1 micron or 20 nanometer resolution (50 microinch or 0.8 microinch), both with 50 mm (2 inch) travel.
  • 1 model for axial/torsional calibrations
  • Provided with calibration traceable to NPL

High Temperature Axial


  • 5 models cover a variety of applications for high temperature testing
  • 1 un-cooled model for use inside chambers up to 700 °C (1300 °F)
  • 4 models for use with split furnaces and induction heating up to 1600 °C

Transverse & Diametral


  • 4 models cover most any test requirement and can be used with axial extensometers at the same time
  • Miniature and standard units
  • Extensometers for r-value of sheet metal
  • Available options cover temperatures from -270 to +200 °C

Average, Bi-axial & Torsion


  • 4 models for axial averaging, axial/transverse, axial/torsional, and in-plane biaxial over a wide range of temperatures
  • Temperatures from -270 to +1600 °C

Knife Edges


  • A complete selection of knife edge styles to match many different specimen types and applications

Calibration References


  • A simple and inexpensive way to transfer Epsilon’s calibration of an extensometer to the signal conditioner in your test system controls