Wheatstone Bridge Balance
Wheatstone Bridge Balance
A Wheatstone bridge measures resistance precisely by balancing it against known resistors until no current flows in the detector.
At balance R_x = R_2·R_3/R_1. where R_1, R_2, R_3 are the known arms and R_x the unknown.
Inputs
R_1 := 100 Ohm=100 Ω
R_2 := 200 Ohm=200 Ω
R_3 := 150 Ohm=150 Ω
Apply the bridge-balance ratio.
R_x := R_2·R_3/R_1=300 Ω
Results
At balance the result depends only on resistor ratios, not the supply voltage, giving an accurate, drift-free measurement.
Assumptions & limitations
- Bridge at balance (null detector).
- Known arm resistances.
- Steady DC.