Unformatted text preview: the apparent strain that results, and comparing that with the expected value of strain associated with the imposed resistance change. The total resistance ( R T ) for two resistors (Gage and Shunt) in parallel is: R T = R G R S R G + R S Eq. 2 For example, consider a 120 Ω strain gage and a 270 k Ω shunt resistor. Using Equation 2, the total resistance for the two combined in parallel is 119.9467 Ω . This represents a change of 0.05331 Ω from the nominal 120 Ω value. Using Equation 1, the strain that would be read, given perfect circuitry and a gage factor of 2.0, for that value of resistance change is C = 0.000222. If your system actually reads a value of M when the shunt resistor is in the circuit, then the correction factor F C is: F C = e C e M Eq. 3 All subsequent measured strain values are multiplied by this correction factor to give a refined estimate of the actual strain value....
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- Spring '08
- Strain, Electrical resistance, strain gage, National Instruments, 0.05331 Ω