Maxwell Inductance Capacitance Bridge

Maxwell Inductance Capacitance Bridge

In this bridge arrangement, the value of unknown inductance is measured by comparison with a variable standard capacitor. Figure 2.13 shows its circuit arrangement and phasor diagram. Two arms bc and ad consist of non-inductive resistance R₂ and R₃. One of the arms ac consists of variable standard capacitor C₄ connected in parallel to a non-inductive resistance R₄. The remaining arm ab consists of unknown inductance L_x of effective resistance R_x. A source of current is applied to two opposite junctions across ac and a null detector is connected to the other two junctions b and d. Hence, the impedances of four arms are

                                      Z₁ = R_x + jwL_x

                                     Z₂ = R₂

                                     Z₃ = R₃