Epsilon ONE – Applications

Composites, Metals, Ceramics


Epsilon ONE is engineered to provide the accuracy and fine resolution required for testing high-modulus materials such as metals, composites, ceramics, and CMCs.

Resolution: <0.2 µm RMS typical at 1 Hz; <0.5 µm at 10 Hz; <1 µm at 100 Hz; <5 nm in low strain rate applications; Typical resolution at selected filter settings

Extensometer Accuracy Class: ISO 9513 Class 0,5 and ASTM E83 Class B-1 or better, typical, for gauge lengths ≥10mm

Epsilon ONE is equipped to measure modulus, offset yield, stress-strain curves, and strain at failure for all of these materials. Precision Telecentric lenses and rigid, well-aligned grips are recommended for these applications.

Plastics, Elastomers

Epsilon ONE’s 200CE optics package can measure more than 1000% strain (200 mm field of view and 10 mm gauge length). The optics and data processing algorithms ensure that specimen marks are tracked even when their contrast is reduced due to specimen extension. This same Optics Package can measure modulus of reinforced plastic microtensile specimens having a gauge length down to 2 mm.

Epsilon ONE is factory calibrated and does not require calibration grids or gauge length bars, saving a great deal of time.

Foil, Wire, Polymer Films

Non-contact strain measurement is the best way, and sometimes the only way, to measure strain with delicate, fine, and thin specimens. Use Epsilon ONE to measure modulus, offset yield, stress-strain curves, and elongation to break with wire, metal foil, polymer film, high-modulus fibers, and polymer filaments. Gauge lengths can be anything between 5 mm and 185 mm with Model ONE-200CE-System, depending on the specimen’s total elongation. Ultra-high camera resolution, real time data rates up to 3000 Hz, and signal processing techniques provide high strain resolution and accuracy with the lowest noise.

Non-Contact COD Gage

KIC, JIC, fatigue crack growth (da/dN) and related applications can be performed using Epsilon ONE as a non-contact COD gage. Its high resolution and accuracy combine with its large measuring range for precise, non-contact JIC and KIC testing. The optical path is very narrow so it can measure crack opening displacement with narrow specimens that are not compatible with clip-on strain gage COD gages.

Epsilon ONE has no moving parts and high real time data rates that allow for fatigue crack growth testing at testing frequencies up to 200 Hz – much faster than clip-on strain gage COD gages.

An Optics Package with a telecentric lens (ONE-78PT-System or ONE-52PT-System) is recommended due to the stringent accuracy requirements and out-of-plane specimen motion in these applications.

Non-Contact Deflectometer

Epsilon ONE is also a non-contact deflection gage. It can measure the initial distance and the change in distance between two coplanar marks that are within the field of view, no matter where the marks are placed. Epsilon ONE can be used in any orientation as long as the marks it is tracking are in the measurement plane. Non-contact deflection measurement of components, assemblies, or structures is possible over a wide range of time scales and either monotonic or cyclic fatigue up to 200 Hz.