Strain Gauge Calculator

A strain gauge bridge configuration refers to how strain gauges are connected in a Wheatstone bridge circuit. Quarter bridge uses one active gauge, half bridge uses two, and full bridge uses four active gauges, each providing different sensitivity levels.

Gauge factor (GF) is a dimensionless number that represents the sensitivity of the strain gauge. Higher gauge factors produce higher output voltages for the same applied strain. Typical metallic strain gauges have GF values between 2.0 and 2.2.

Quarter bridge uses one active gauge with three completion resistors, half bridge uses two active gauges, and full bridge uses four active gauges. Full bridge provides the highest sensitivity (4x quarter bridge), followed by half bridge (2x quarter bridge).

Excitation voltage powers the Wheatstone bridge and directly affects the output signal amplitude. Higher excitation voltage increases signal strength but may cause self-heating in the gauge, potentially affecting accuracy.

Use higher excitation voltage (within gauge limits), choose full bridge configuration when possible, use proper shielding, minimize cable length, and select gauges with appropriate gauge factors for your application.

Strain is typically measured in microstrain (με), where 1 με = 1 × 10⁻⁶ strain. This unit is convenient because most engineering strains fall within the range of hundreds to thousands of microstrains.

Modern strain gauges can achieve accuracies of ±0.1% to ±0.5% of full scale under controlled conditions. Accuracy depends on factors like temperature compensation, gauge quality, installation technique, and measurement electronics.

Output voltage depends on gauge factor, applied strain, excitation voltage, and bridge configuration. Temperature changes, gauge resistance, and electrical noise can also affect the output signal quality.