Extensometer

File:Extensometer.jpg

extensometer

SlideMinder Extensometer

Non contact extensometry3

Videoextensometer1

Extensometer

An extensometer is a device used to measure the change in length of an object. It is commonly used in materials science, mechanical engineering, and structural engineering to determine the strain of a material under various conditions. Extensometers are essential tools in tensile testing, compression testing, and other forms of mechanical testing.

History

The concept of the extensometer dates back to the early developments in the field of materials testing. The first extensometers were mechanical devices, but modern versions often use electronic components to provide more accurate and reliable measurements.

Types of Extensometers

There are several types of extensometers, each suited for different applications:

• Contact Extensometers: These devices physically attach to the specimen being tested. They can be further classified into:

 * Clip-on Extensometers
 * Averaging Extensometers

• Non-contact Extensometers: These devices use optical or laser technology to measure strain without physically touching the specimen. Examples include:

 * Laser Extensometers
 * Video Extensometers

Applications

Extensometers are used in various fields, including:

• Materials science: To study the properties of materials under different conditions.
• Mechanical engineering: For testing the mechanical properties of components and structures.
• Structural engineering: To monitor the behavior of structures under load.

Operation

The basic principle of an extensometer involves attaching the device to a specimen and measuring the change in length as the specimen is subjected to a load. The data collected is then used to calculate the strain, which is a measure of deformation.

Calibration and Accuracy

Calibration is crucial for ensuring the accuracy of an extensometer. Regular calibration against known standards is necessary to maintain the reliability of the measurements. Factors such as temperature, alignment, and the condition of the specimen can affect the accuracy of the device.

Related Pages

• Strain gauge
• Tensile testing
• Compression testing
• Mechanical testing
• Materials science
• Mechanical engineering
• Structural engineering

See Also

• Stress (mechanics)
• Elasticity (physics)
• Deformation (mechanics)