1. Wheatstone Bridge
Discussion D2.6

2. Wheatstone Bridge
Measuring Resistance
Strain Gauges

3. Wheatstone Bridge
Note that if
and
then
Why?

4. Wheatstone Bridge

5. Measuring Resistance, R3
Solving for R3

6. Wheatstone Bridge
Measuring Resistance
Strain Gauges

7. Strain Gauge
Definition of strain, e
Force
Force L DL

8. Strain Gauge Recall r = resistivity in Ohm-meters l A Force Force
= length
Resistance
Under axial strain, l increases and A decreases so the resistance R increases

9. Strain Gauge
Gauge factor, GF

10. Measuring Strain, e
Solving for e