1.5

Force, pressure and flow

1.5.1 Strain gauge

A strain gauge is a metal or semiconductor whose resistance changes markedly when it is deformed. The deformation is usually taken to be a measurement of strain, and hence force, applied to a structure.

The resistance of a specimen of material of length 1 and cross-sectional area A is given by:

image

A change in length or area with strain produces a change in resistance of a particular element.

If the resistance of a particular element is Ro with no strain, then the strain gauge factor G is given by:

Strain gauges typically carry only a small current (15 – 100 mA) to avoid self-heating changes in ...

Get Newnes Interfacing Companion now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.