How Do Extensometers Work?

Extensometers are designed to measure minute changes in length, with some types capable of measuring changes smaller than one millionth of an inch. The fundamental operation of an extensometer involves a sensitive device that measures the change in distance between two points, which are typically affixed to the material under test.

Types of Extensometers

When you start exploring extensometers, you'll find many different types. Each one is specially made to work best in certain conditions and for specific needs. Now let's look at the main types of extensometers to better understand how they do their job.

• Contact Extensometer: Contact extensometers physically attach to the sample being tested, directly measuring the changes in length as the sample is deformed.
• Laser Extensometer: Non-contact extensometers use visual or laser methods to measure deformation without physically attaching to the sample. This is particularly useful in high-temperature or high-strain applications, where contact with the specimen might compromise the test results.
• Video Extensometer: A type of non-contact extensometer, video extensometers use a series of cameras to track the movement of markers on the specimen during the test, providing highly accurate measurements of strain.
• Clip-On Extensometer: Clip-on extensometers are a type of contact extensometer that is easily attached to the test specimen. They are often used for standard tensile tests and are designed to measure axial strains on a test specimen.

Applications of Extensometers

Extensometers hold pivotal roles across diverse sectors, from aerospace and manufacturing to construction and vehicle weighing systems, aiding the evaluation of mechanical characteristics such as acting loads, contents of vessels or conditions of vehicles and structures.

Common applications include:

• Construction: Extensometers are indispensable in assessing how structures deform under load, thereby reinforcing the safety and durability of constructions such as buildings and bridges.
• Aerospace: They're key to testing the resilience and pliability of different materials under varied conditions, ensuring suitability for aviation and space exploration.
• Manufacturing & Research: In manufacturing and research institutions alike, extensometers underpin the assurance of product quality and structural integrity, supplying essential data for design and process control.
• On-Board Vehicle Weighing: An extensometer plays a crucial role in on-board vehicle weighing systems, translating the strain experienced by a vehicle's structure into weight readings. This proves invaluable for real-time load weight monitoring, thus avoiding overloading, improving logistical efficiency, and ensuring adherence to vehicle weight regulations.
• Silo Measurement: Extensometers are also widely used for silo measurement in agricultural and industrial sectors. They monitor the strain within the silo structure due to material load, enabling accurate estimation of the quantity of the stored material. This ensures efficient inventory management and aids in the detection of any structural issues with the silo, thereby enhancing operational safety and efficiency.

Choose the Right Extensometer

The choice of the right extensometer is dependent on multiple factors such as the material being tested, the expected degree of deformation, the environmental conditions, and the desired accuracy of the measurements.

At Flintec, we offer a range of extensometers that can be used within various industrial applications. We are also able to develop customised extensometers, developed to meet your exacting needs.