Extensometer Its Types
Extensometer: An extensometer is an instrument that is used to measure changes in the length of an object.It is useful for stress-strain measurements and tensile tests. Its name comes from "extension-meter". It was invented by Charles Huston who described it in an article in the Journal of the Franklin Institute in 1879. Huston later gave the rights to Fairbanks & Ewing, a major manufacturer of testing machines and scales. There are two main types of extensometers: 1.contact 2.non-contact. Contact Extensometer: Contact extensometers have been used for many years and are also subdivided into two further categories. The first type of contact extensometer is called a clip-on extensometer. These devices are used for applications where high precision strain measurement is required (most ASTM based tests). They come in many configurations and can measure displacements from very small to relatively large (less than a mm to over 100 mm). They have the advantage o...