Work out strain gauge output instantly with clear inputs, formula shown and shareable results.
Bridge output is Vex x GF x strain x (active arms)/4. A quarter bridge at 450 microstrain with a gauge factor of 2.1 and 5 V excitation gives just 1.2 mV, which is why strain measurement needs a low-noise instrumentation amplifier with gain in the hundreds.
Strain bridge output
Vout = Vex x GF x strain x arms / 4
Four times the output of a quarter bridge, plus inherent cancellation of temperature effects and bending or axial components depending on the arrangement.
One part per million of length change. Steel yields at roughly 1,500 microstrain, so working measurements are typically a few hundred.