2. Sensor wiring diagram

2.1 Bridge circuit principle

Consider a circuit consisting of four equal resistors R ₁ , R ₂ , R ₃ , R ₄ connected in a bridge configuration (figure 2 ). If we supply it with a current source P along a diagonal, we have at equilibrium a zero voltage between B and D. The variation of any one of the resistors causes a voltage V _s to appear between B and D, which can be measured by an instrument G. For very small variations in resistance (of the order of a few microohms in...