top of page

Epsilon's February Newsletter

Following on from our January newsletter, and the positive feedback we received, this month we are going to highlight the Epsilon Knowledge Centre, the Epsilon ONE and the Epsilon Model 3575.

The Epsilon Knowledge Centre is a great first stop for all of your Epsilon related queries, here you will find ‘Extensometer Tech Notes’, an ‘Extensometer Video Library’ and an ‘Extensometer Basics’ sections as well.

Within the ‘Extensometer Tech Notes’ section you will be able to find documentation cover a wide variety of topics from Calibration and Verification to Optimizing Test Results and Data Quality, it really is a very useful tool.

The ‘Extensometer Video Library’ contains a wide range of videos, from product demonstrations, to installation and set-up.

Finally, ‘Extensometer Basics’ which, as described, talks about the very of extensometry such as ‘what is gauge length?’ to how they are interfaced with testing machines.

Epsilon ONE - Precision Optical Extensometers

The Epsilon ONE is a high-precision optical extensometers measure axial strain with industry-leading resolution, accuracy, and speed. Innovative Instant Reset and Laser Alignment features maximize ease of use and testing throughput. ±10V output is compatible with any testing system.

Precision - Optical Non-Contacting.jpeg

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.

Model 3575 - Transverse (Diametral) Extensometers

Designed for general purpose transverse or diametral strain measurement on axially loaded specimens. The model 3575 may be used simultaneously with the Model 3542 axial extensometer.

Model 3575.jpg

Self-supporting on the test sample, these extensometers will work on any width or diameter specimen from 0 to 25 mm (0-1 inch). Most often they are used simultaneously with Epsilon’s axial extensometers, and together these extensometers are suitable for measurement of Poisson’s ratio per ASTM E132, for transverse measurements with anisotropic materials like many composites, and for r-value testing of sheet metal specimens per ASTM E517.

These units easily clip onto the sample and are held in place with an integral spring. Rounded contact surfaces maintain the position on the specimen. All models are high accuracy strain gaged units.

Model 3575 extensometers are strain gaged devices, making them compatible with any electronics designed for strain gaged transducers. Most often they are connected to a test machine controller with electronics for a strain channel, and Epsilon will equip the extensometer with a compatible connector that is wired to plug directly into the controller. For systems lacking the required electronics, Epsilon can provide a variety of signal conditioning solutions that enable connecting to data acquisition systems or other equipment.

Epsilon's January Newsletter

As the new year begins, we are DWE Scientific Ltd would like to wish you all the best for 2024!

During 2024, we are going to be releasing monthly newsletters highlighting the good and great of Epsilon products, from new product releases to highlighting some of the fantastic products already available.

Some of you may have already seen out post on LinkedIn back in December highlighting the ‘Quick to Ship’ program, the “Quick To Ship” program allows  popular model 3542 extensometers to be configured and shipped within 5 working days. In most cases, we can factory fit the connector required for your brand of test machine.


Model 3549 - High Temperature Hot Mountable Furnace Extensometers (1200°C or 1600°C)

The Epsilon model 3549 is designed to be used for static and fatigue testing when using split type materials testing furnaces or induction heaters. It is designed to meet the stringent requirements of Closed-loop strain control testing as prescribed in ISO 6892, ISO 12106, ASTM E21, and ASTM E606, while introducing many innovative features that improve productivity and performance for static tensile testing, long-term testing such as low cycle fatigue and creep, and other applications requiring small strain measurements.


The overall design reduces influence from common lab environment like vibrations, thermal noise, and thermal drift. It also allows the user to precisely set the required contact force against the test specimen. This allows for even and repeatable contact force, limiting contact force induced errors.

The gauge length for the 3549 is automatically set prior to contact/mounting on the test specimen, which allows for hot loading/mounting after specimen thermal equilibrium has been reached. These extensometers can be used in carousel systems for rapid high temperature testing.

This extensometer mounts on a slide bracket (included) that attaches to a load frame mounting bracket or directly to a furnace that has a suitable cutout. We can supply mounting brackets for nearly any load frame.

The -ST version is rated to 1200 °C (2200 °F) and is supplied with high purity alumina rods. The high temperature -HT option allows use to 1600 °C (2900 °F) and is supplied with alpha grade silicon carbide rods. Rods are made to order to the length required for your furnace.

Model 3549 extensometers are strain gaged devices, making them compatible with any electronics designed for strain gaged transducers.

Model 3442AVG - Averaging Axial Extensometers

The all-purpose Epsilon model 3442AVG averaging axial extensometer is used in tension or compression to measure Young’s modulus, offset yield, and strain to failure. It is compact and lightweight, and Gauge length is set automatically for fast specimen mounting.

Model 3442AVG.jpg

The Model 3442AVG is optimized for high-accuracy tension and compression testing. It measures strain simultaneously on opposite sides of the specimen to average out specimen misalignment while measuring axial strain.

The averaging capability is useful for measuring Young’s modulus per ASTM E111, properties of composite materials per ISO 527 and ASTM D3039, and compression of metals per ASTM E9.

It is compact, lightweight, and may be used through specimen failure with most materials. It is fatigue rated and may be used in strain control.

The extensometer sets its gauge length automatically when it is mounted on the specimen. This feature improves repeatability, reduces operator errors and saves time. Just mount the extensometer and it will be at its gauge length and ready for testing.

Output can be configured in two ways: with a single output for average strain measurement, or with separate outputs for measuring strain separately on opposite sides of the specimen with two strain channels. The configuration with two outputs can be used during test setup or during the test to measure specimen bending (strain uniformity) caused by misalignment or specimen machining imperfections.

To measure Poisson’s ratio, the Model 3442AVG may be used in combination with a transverse adhesively bonded strain gage, or other other extensometers may be used such as Model 3560BIA or Model 3542 in combination with Model 3575.

Model 3442AVG extensometers are strain gaged devices, making them compatible with any electronics designed for strain gaged transducers.

If you would like any information regarding either of the extensometers listed above, the ‘Quick to Ship’ program, or any other Epsilon products, please feel free to contact us by either responding to this email, or using the ‘Contact Us’ section of our website.

bottom of page