README.md

ME 3263 Introduction to Sensors and Data Analysis (Fall 2018)
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Lab #2 - Static beam deflections with strain gage
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# What is a Strain Gage?

A strain gage consists of a looped wire that is embedded in a thin backing. Two
copper coated tabs serve as solder points for the leads. See Figure 1a. The
strain gage is mounted to the structure, whose deformation is to be measured. As
the structure deforms, the wire stretches (increasing its net length ) and its
electrical resistance changes: $R=\rho L/A$, where $\rho$ is the material
resistivity, $L$ is the total length of the wire, and $A$ is the cross sectional
area of the wire.  Note that as $L$ increases, the cross sectional area changes
as
well due to the Poisson contraction; the resistivity also changes.

![Figure 1: a) A typical strain gage. b) One common setup: the gage is
mounted to measure the x-direction strain on the top surface. It's
engaged in a quarter bridge configuration of the Wheatstone bridge
circuit.](./figure_01.png)

*Figure 1: a) A typical strain gage. b) One common setup: the gage is
mounted to measure the x-direction strain on the top surface. It's
engaged in a quarter bridge configuration of the Wheatstone bridge
circuit.*