Back to category: Science

Limited version - please login or register to view the entire paper.

The Wheatstone Bridge

Introduction
In 1843 the English physicist Sir Charles Wheatstone (1802-1875) found a bridge circuit for the measurement of electrical resistances. In this bridge circuit, known today as the Wheatstone bridge, unknown resistances are compared with well defined resistances (1). The Wheatstone bridge is well suited also for the measurement of small changes of a resistance and, therefore, is also suitable to measure the resistance change in a strain gauge. It is commonly known that the strain gauge transforms strain applied to it into a proportional change of resistance. The relation between the applied strain ( = L/Lo) and the relative change of the resistance of a strain gauge is described by the equation
(Equation 1)
The factor k, also known as the gauge factor, is a characteristic of the gauge used for strain measurement and is to be checked experimentally (2). Below, the Wheatstone bridge circuit will only be considered with respect to its application in strain gauge techniques....

Posted by: Carlos Hernandez

Limited version - please login or register to view the entire paper.