2. A strain gauge (see picture shown below from Omega) is a resistance element that is used to measure the fractional elongation experienced by a material. If it is attached to a beam that undergoes a deflection due to an impact, we can use the gauge to measure the deflection or monitor the frequency with which the beam vibrates. R1 SG1 Lunn Assume we attach two strain gauges (SG1 and SG2) on opposite sides of the beam as shown above. If the beam deflects downward, SG1 elongates (so its resistance increases) while SG2 compresses (so its resistance decreases). Let's hook up the elements into a Wheatstone bridge as shown below. If R1=R2=100 2, and the nominal values of SG1 and SG2 when no strain is present are 100 as well, what is the value of Vout when the beam is deflected enough to cause SG1 to increase to 100.1 2 and SG2 to decrease to 99.9 ? The voltage at the top of the bridge (10V in this case) is called the "excitation voltage". 9 10V Vout R2 Wall SG2 SG 1 SG 2 Beam

2. A strain gauge (see picture shown below from Omega) is a resistance element that is used to measure the fractional elongation experienced by a material. If it is attached to a beam that undergoes a deflection due to an impact, we can use the gauge to measure the deflection or monitor the frequency with which the beam vibrates. R1 SG1 Lunn Assume we attach two strain gauges (SG1 and SG2) on opposite sides of the beam as shown above. If the beam deflects downward, SG1 elongates (so its resistance increases) while SG2 compresses (so its resistance decreases). Let's hook up the elements into a Wheatstone bridge as shown below. If R1=R2=100 2, and the nominal values of SG1 and SG2 when no strain is present are 100 as well, what is the value of Vout when the beam is deflected enough to cause SG1 to increase to 100.1 2 and SG2 to decrease to 99.9 ? The voltage at the top of the bridge (10V in this case) is called the "excitation voltage". 9 10V Vout R2 Wall SG2 SG 1 SG 2 Beam