Precision Optical Extensometers - Epsilon ONE

Precision Optical Extensometers - Epsilon ONE

Epsilon One non-contacting Extensometer

Breakthrough Performance  •  Incredibly Easy to Use  •  Works With Any Test Machine


Epsilon ONE® high-precision optical extensometers measure axial strain with industry-leading resolution, accuracy, and speed. Innovative Instant Reset, Always On and Laser Alignment features maximize performance and increase testing throughput.

Why Non-Contact:

  • One system for many different tests, measuring ranges, and gauge lengths

  • Test through failure with high-energy specimens

  • Test fine, delicate specimens without unwanted influence or contact stresses

Why Epsilon ONE®:

  • Performance: industry-leading resolution, accuracy and ease of use

  • Instant Reset: ready to test in under 2 seconds

  • High Speed: cyclic testing at 100+ Hz and real-time data rates up to 3000 Hz

  • Precision by Design: better non-contact testing with Laser Alignment and Telecentric Optics

Epsilon ONE® optical non-contact extensometers perform high-accuracy, high-resolution, non-contacting axial strain and displacement measurement. These extensometers are suitable for testing high-modulus materials such as metals and composites, high-elongation materials, thin or delicate specimens, cyclic fatigue, strain controlled testing, deflectometer applications, and measuring crack opening displacements. Strain or extension is measured and output in real time.

Epsilon ONE’s high resolution and ISO 0,5 / ASTM B-1 accuracy classes make it suitable for non-contact measurement of a wide range of strain values, from very small strains required to measure modulus* of metals, composites, ceramics and CMCs through elastomers and everything in between.

Class-leading accuracy and resolution are achieved by Epsilon’s comprehensive optical path optimization, a unification of several optical technologies and signal processing algorithms. Ultra-high camera resolution, real-time data rates up to 3000 Hz, minimization of optical error sources, and signal processing techniques provide high strain resolution and accuracy with the lowest noise. No other system on the market combines all of these technologies.

The Laser-Assist Alignment System provides an instant alignment and distance spot check. Epsilon ONE will project pre-aligned laser lines on the specimen before the test, revealing any misalignment. During the test, high precision telecentric lenses on the PT models eliminate errors due to out-of-plane movements – a common source of errors for many video extensometers. Epsilon ONE arrives factory calibrated – there are no calibration grids or gauge length bars, saving a great deal of time.

The system sets up for new specimen types in minutes and requires very little training or skill to use. The desktop user interface software and optional Touch Interface provide continuous digital readouts and status information.

Epsilon ONE was designed for the fastest specimen cycle times. Auto-start repetitive tests without any software interaction; Epsilon ONE is always running, and its Instant Reset and Automatic Mark Detection eliminate software start/stop interactions common with video extensometers.

Epsilon ONE provides a calibrated ±10V strain signal as an input for the testing machine’s controller. The extensometer fits all types of materials testing machines, including machines that have an environmental chamber with a window (contact Epsilon for fitment).

*As with clip-on extensometers, accurate measurement of modulus requires a well-aligned load train and grips, and symmetrical specimens that are centered in the grips. Gauge lengths ≥25 mm are recommended in most cases. Contact Epsilon for additional Best Practices.