Extensometers

Extensometers from Universal Grip​​​

Universal Grip offers the industry's widest selection of extensometers for tensile, compression, and flexural testing. Our strain measurement systems are engineered for precision, reliability, and compatibility with virtually any brand of universal testing machine (UTM) or tensile testing machine, including Instron, MTS, Shimadzu, Tinius Olsen, Galdabini, and more.

If you need an extensometer for materials testing—whether it’s a non-contact extensometer, clip-on extensometer, or video extensometer—Universal Grip has a solution to fit your application and budget.

Industry-Leading Strain Measurement Systems

Our extensometers are designed to work seamlessly with any testing machine equipped with a strain gauge input channel. Each system outputs a calibrated 0–10 V signal over the selected gauge length, making integration simple and reliable.

Key features of our extensometers include:

• Broad compatibility with leading brands (Instron, MTS, Shimadzu, Tinius Olsen, Galdabini, and others)

• Easy integration with existing test machine controllers

• Plug-and-play interface support

• Precise, repeatable strain measurement for compliance with ASTM and ISO standards

Types of Extensometers Available

Universal Grip carries a complete range of extensometer types to support diverse materials testing applications:

Vector 3D Non-Contact Extensometer

Our flagship system, the Vector 3D Non-Contact Extensometer, uses advanced Digital Image Correlation (DIC) techniques for strain measurement without physical contact with the specimen. Featuring an onboard GPU for high-speed processing and enhanced measurement accuracy, it delivers:

• Full-field 2D/3D strain mapping

• No damage to delicate or high-elongation specimens

• User-friendly software interface

• Reliable results even on challenging materials or geometries

Clip-On Extensometers

We offer a wide selection of clip-on extensometers, ideal for standard tensile testing of metals, plastics, composites, and more. Features include:

• Robust, lightweight designs

• Wide range of gauge lengths and travel

• Compatible with most grips and fixtures

• ASTM-compliant accuracy and repeatability

Long-Travel and Balanced Extensometers

For applications requiring greater extension measurement—such as elastomers, rubber, and highly ductile materials—we provide long-travel extensometers that mount directly to the testing machine. These systems are balanced for smooth operation and accurate strain capture over large elongations.

2D Video Extensometers

We also offer 2D video extensometers, which deliver high-resolution strain measurement using advanced camera and software systems. Benefits include:

• Contact-free operation

• Easy specimen preparation

• Real-time video analysis

• Suitable for a variety of sample sizes and materials

Extensometer Integration and Compatibility

Unlike some vendors who lock you into proprietary systems, Universal Grip’s extensometers are universal by design. We can assist with cabling, signal conversion, and plug interfaces to ensure your new extensometer integrates flawlessly with your existing test frame—regardless of brand or model.

We support customers looking to:

• Replace aging or expensive OEM extensometers (e.g. Instron extensometer replacement)

• Upgrade to non-contact extensometer technology

• Add new extensometer capability to legacy testing machines

Laser Extensometer Alternatives

Note: Universal Grip does not supply laser extensometers. Laser extensometer technology is being phased out across the industry in favor of modern Digital Image Correlation (DIC) and video extensometer solutions, which offer better versatility, lower cost, ease of use, and measurement fidelity.

Why Choose Universal Grip for Your Extensometer Needs?

• Industry expertise: Over a decade of experience in materials testing equipment

• Comprehensive selection: The widest range of extensometer types for any budget or requirement

• Technical support: Guidance for selecting, installing, and integrating your extensometer

• Quality guarantee: Rugged, precise, and dependable measurement systems

Request a Quote or Learn More

Ready to find the perfect extensometer for your universal testing machine? Contact Universal Grip today to discuss your requirements, request a quote, or get expert advice on selecting the right strain measurement system for your testing program.

What is an Extensometer?

An Extensometer is a type of strain gauge that is used in conjunction with a Universal Testing Machine in order to measure elongation at high accuracies. Extensometers come in different shapes and sizes depending on the type of sample being measured. Extensometers can also be used to measure in the lateral direction in order to observe and quantify changes to the material in the X reference plane. Poisson’s Ratio is a specific calculation that combines XY strain gauge extensometer measurements in order to characterize the necking effect . Poisson’s calculation is commonly used in Metallurgy to characterize different types of commercial grade steel, especially cold rolled steel sheets.

Clip-On Extensometers

Clip-on extensometers are the most common and lowest cost type, however these measurement instruments have a tendency to fall from the test apparatus and break.  Clip-on extensometers are commonly used for tensile tests involving metal and are removed before a sample break occurs. There are two main specifications for a clip-on extensometer. The first is the distance between the two reference points which are two equidistant points inside the neck area of the sample - usually 1” or 2” apart. The second specification is the amount of elongation to be measured. Brittle metals will have elongation of less than 10%, where as a more ductile metal like Aluminum may have up to 50% elongation.​

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Balanced Extensometers

Balanced Extensometers are used for materials such as elastomers, plastics, and textiles that could have elongations above 50% or 100%. These types of extensometers are supported by the machine and hang off to the side. When a sample is loaded into the grips, the long travel extensometer will swivel into place and attach onto the sample.  The extensometer will stay attached throughout the test including during the sample break. Universal Grip offers the Micron extensometer which is used in conjunction with the Galdabini Graphworks 6 testing software.  The Micron extensometer is capable of measuring elongations of over 1000% which are usually seen when testing thermoplastic elastomers.

Other Types of Strain Measurement

Extensometers are used exclusively for tensile testing. Similar devices are used for compression and bend tests, however they are slightly different. Compression tests, such as those involving concrete cylinders, will use a type of strain gauge called a Compressometer. Bend tests will use a deflectometer which is able to accurately measure the deflection of the bend testing specimen. These types of contact measurement methods are much more precise than simply using the crosshead position data from the materials testing system.  The extensometer is in direct contact with the sample and therefore gives a much more accurate representation of what is happening during the test procedure. 

Measuring Elongation in an Environmental Chamber

If the extensometer is used in an environmental chamber, special precautions must be taken in order to account for the temperature. Specially designed high temperature extensometers that can withstand over 1000 degrees Celsius are available from Universal Grip. The high temperature extensometers use ceramic components in order to withstand the harsh conditions. If you have more questions regarding these types of strain gauge measurement devices, please contact us.