Learn about extensometers with these short videos showing extensometer applications, demonstrations and setups.

The all-purpose Model 3542 extensometer https://epsilontech.com/3542 measures strain for determining elastic modulus, offset yield strength, ultimate elongation, and many other properties. The extensometer is mounted on the specimen with the gauge length pin (or ''zero pin'') in place to set the extensometer''s gauge length accurately. The operator then removes the pin and starts the testing machine. As the testing machine pulls the specimen in tension, the extensometer measures strain while the testing machine measures force. Stress is calculated by dividing the force on the specimen by its initial cross sectional area. As the test runs, the initial stress-strain response of this metal specimen is linear. This is the elastic modulus region where stress is proportional to strain. Next, yielding, or permanent deformation, begins to occur and the stress-strain plot curves to the right. Using the stress and strain data, the offset yield stress value is measured in this example.

Rebar testing through failure requires an especially rugged extensometer. For measuring tensile strain at break, the durable Model 3543 extensometer https://epsilontech.com/3543 may be left on through rebar failure. The extensometer splits into two pieces so that it doesn't have to absorb the full shock when the rebar breaks, and the Quick Attach feature makes extensometer attachment easy and reliable. Model 3543 extra-durable extensometers are used for rebar strain measurement and similar testing applications where there is a large energy release at specimen break. The wireforms shown in this video are not the standard wireforms.

The compact Model 3442 extensometer https://epsilontech.com/3442 measures strain in this tensile test through failure of AISI 1080 high strength steel. The music wire rod in this test has a 4.7 mm diameter. The extensometer may be used for determining elastic modulus, offset yield strength, ultimate elongation, and stress-strain curves. It may be left on through failure. This miniature extensometer is especially suited for tension and compression testing in tight spaces and with short specimens. It is light weight and suited for delicate specimens. It may be used in strain control and it is fatigue-rated. Product web page: https://epsilontech.com/3442

The Model 3442AVG averaging axial extensometer https://epsilontech.com/3442AVG accurately measures average axial strain of composites and most high-modulus materials, including measurement of elastic modulus. The extensometer''s gauge length is self-setting, which improves repeatability and simplifies operator handling; gauge pins are not needed. The extensometer can be configured with two separate outputs so that % bending can be measured in addition to average axial strain when the testing equipment has two strain channels. The extensometer clips onto the test specimen in one simple motion and is applicable for testing to the following standards:

• ASTM D3039 Tensile Properties of Polymer Matrix Composite Materials
• ASTM D3553 Tensile Properties of Fiber Reinforced Metal Matrix Composites
• ISO 527-4 and 527-5 Test Conditions for Fiber-Reinforced Plastic Composites
• ASTM E111 Standard Test Method for Young''s Modulus
• ASTM E9 Compression Testing of Metallic Materials

The Model 3421 clip-on extensometer http://epsilontech.com/3421 can be used to measure shear modulus, 2% offset shear strength, and shear stress - shear strain curves for the following applications:

• Honeycomb and foam sandwich core materials
• Rigid cellular plastics

The extensometer clips onto the test specimen in one simple motion and is applicable for testing to the following standards:

• ASTM C273 Shear Properties of Sandwich Core Materials
• ASTM C394 Shear Fatigue of Sandwich Core Materials
• ISO 1922 Rigid cellular plastics - Determination of shear strength
• DIN 53294 Testing of sandwiches; shear test
• EN 12090 Determination of Shear Behavior of Thermal Insulation Products (single specimen test only)

This video shows how a telecentric lens nearly eliminates extensometer measurement errors from out-of-plane movements that are typical with specimens that are not straight. For example, tensile specimens made from metal strip that was coiled may have some curvature. Product web page: https://www.epsilontech.com/products/... This video features the image "Bi telecentric lens Schneider" by Laserlicht, available under CC BY-SA 4.0 license.

high-resolution optical extensometer - Epsilon ONE® overview (Epsilon Technology)

The Model 3800 extensometer http://epsilontech.com/3800 is for rubber and elastomer tensile testing. Use it to measure tensile modulus, elongation at break, yield strain, and stress-strain curves of high-elongation materials. Full scale measuring ranges are available from 500% to 2500% strain. The extensometer may be left on the specimen through failure. Applicable standards: ASTM D412 Epsilon Technology: http://epsilontech.com

The model 3742 extensometer sets its gauge length automatically - faster testing, easier setup. See more at www.epsilontech.com/3742.

The model 3742 extensometer'' Quick Swap feature lets you change gauge lengths in less than 10 seconds - faster testing, easier setup. See more at www.epsilontech.com/3742.

The Epsilon ONE® optical non-contact extensometer performs axial strain measurement for materials testing. Breakthrough Performance • Incredibly Easy to Use • Works With Any Test Machine

Determining what Field of View you require is important when buying a video extensometer. This video shows a simple experimental technique that lets you quickly estimate the minimum required Field of View for a particular specimen. Product web page: https://epsilontech.com/products/opti... Website: https://epsilontech.com

Epsilon ONE® optical extensometer - specimen marking

Epsilon ONE® - Touch Interface demo