Wheatstone and strain bridge
Wheatstone and strain bridge with explicit circuit assumptions and worked equations.
Development preview. Check the assumptions below before relying on a result. Calculations run in your browser.
How it calculates
Exact output: Vout = Vexc[R4/(R3+R4) − R2/(R1+R2)]
Gauge change: ΔR/R = GF × strain
Assumptions
- R1/R2 are the top/bottom left leg; R3/R4 are the top/bottom right leg. Output is right midpoint minus left. Half bridge puts tension/compression in R1/R2; full bridge adds compression/tension in R3/R4. Unloaded bridge; lead resistance and temperature compensation are omitted.
Worked example
These are the calculator's default inputs. Change any input above to recalculate.
Inputs
- Bridge
- quarter
- Excitation
- 5 V
- Gauge nominal resistance
- 350 Ω
- Gauge factor
- 2
- Strain
- 1000 µε
- Top left R1
- 350 Ω
- Bottom left R2
- 350 Ω
- Top right R3
- 350 Ω
- Bottom right R4
- 350 Ω
Results
- Right minus left output
- 0.0024975 V
- Linear approximation
- 0.0025 V
- Exact minus linear
- -0.0000024975 V
- Bridge output
- 0.4995 mV/V
- Common-mode voltage
- 2.49875 V
- Differential source resistance
- 350.175 Ω
- Excitation power
- 0.0713929 W