Electrical Resistance Strain Gages - Essay Example

The most common and accepted method of measuring strain is using the electrical resistance strain gage.

The strain gauge is a gaunt conductor made of a wire or a metallic foil that is in a grid-like pattern. In particular, the grid-like pattern maximizes the amount of strain in the parallel direction. The experiment uses a conductor (carrier) that is of thin strips of metallic film placed on a non-conducting substrate material. The wire is to the specimen and facilitates the transfer of the strain from the specimen to the strain gauge. Accordingly, the transfer makes a linear change in the electrical resistance. Precisely, the electrical resistance of a conducting wire fluctuates when the length of the conductor changes in a process called deformation or stretching. Consequently, the basis of the electrical resistance strain gauge is the deformation. Under an ideal situation, the strain gage resistance ranges between 30 Ω to 3 kΩ. Fundamentally, the resistance changes only a fraction of a percent in a full-force range of the gauges. For this reason, a higher resistance change causes a permanent deformity to the test specimen. Therefore, successful use of the strain gauge calls for a measure of small changes under high accuracy.