A Universal Testing Machine (UTM) is a piece of mechanical testing equipment used to evaluate the physical properties of materials, including tensile, compressive, bending, and shear strength. It operates by applying a precisely controlled tensile or compressive force to a test specimen and measuring how the material responds under load.

Extensometer FAQs

What does an extensometer measure?

An extensometer measures strain, which is the change in length of a specimen divided by its original gauge length during mechanical testing.

Why are extensometers more accurate than crosshead displacement?

Crosshead displacement includes deformation from the test frame, grips, and fixtures. Extensometers measure strain directly on the specimen, providing more accurate material property measurements.

What is the difference between a clip-on extensometer and a video extensometer?

A clip-on extensometer attaches directly to the specimen and measures displacement between two points. A video extensometer measures strain optically using cameras and image analysis without contacting the specimen.

When is a long-travel extensometer required?

Long-travel extensometers are used when materials experience very large elongations, such as elastomers, thermoplastics, and textiles.