What Is the Wheatstone Bridge Resistor & Strain Gauge Calculator?
The Wheatstone bridge is an electrical network of four resistor arms used to detect minute variations in electrical resistance.
How Does the Wheatstone Bridge Resistor & Strain Gauge Calculator Work?
When the ratios of the arms are equal (R1/R2 = R3/Rx), the potential difference between the center midpoints is exactly zero volts.
Wheatstone Bridge Resistor & Strain Gauge Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Balanced Rx equals R2 times R3 over R1. Output voltage is excitation times difference of voltage divider fractions.
How to Use the Wheatstone Bridge Resistor & Strain Gauge Calculator
- Enter the bridge excitation supply voltage (e.g. 5V, 10V, or 12V).
- Input the known bridge arm resistances R₁, R₂, and R₃.
- Enter the sensor gauge resistance Rx.
Step-by-Step Example Calculation
1,000 Ω Quarter-Bridge with 20 Ω Gauge Deflection
Input Values:
Understanding Your Result
Differential Output (V_out): Millivolt reading across center terminals.
Balanced Null Rx: Resistor value required to achieve zero output voltage.
Bridge Sensitivity: Millivolts of output change per Ohm of resistance change.
Factors That Affect the Result
- Excitation voltage (directly scales Vout), initial bridge arm matching, and gauge lead wire resistance.
When Should You Use This Calculator?
- Load cell weighing scales, structural strain monitoring, aerospace wing testing, and RTD temperature transmitters.
Assumptions & Limitations
- Assumes high input impedance instrumentation amplifier reading Vout (negligible output load current).
Frequently Asked Questions
Calculation Accuracy & Reference Note
Exact nodal analysis solution of balanced/unbalanced resistive bridge networks.