De Sauty Bridge Notes for Electrical Engineering Students The De Sauty Bridge is an AC bridge used to measure an unknown capacitance by comparing it with a known standard capacitor. It is one of the simplest bridge circuits used in electrical and electronics engineering laboratories for capacitance measurement. The bridge operates on the principle of bridge balance, similar to the Wheatstone Bridge. When the bridge reaches a balanced condition, no current flows through the detector, allowing the unknown capacitance to be calculated accurately. A De Sauty Bridge is an electrical measuring instrument that determines the value of an unknown capacitor by comparing it with a known standard capacitor using the AC bridge balancing principle. Principle of the De Sauty Bridge The De Sauty Bridge works on the bridge balance principle. When the impedance ratios of opposite bridge arms are equal, the detector shows zero current. At the balance point: Z₁/Z₂ = Z₃/Z₄ Since the bridge contains capacitors and resistors, the unknown capacitance can be determined using the known values. Circuit Diagram The De Sauty Bridge consists of four bridge arms: Arm 1 – Standard capacitor (Cs) Arm 2 – Unknown capacitor (Cx) Arm 3 – Resistance R1 Arm 4 – Resistance R2 An AC source is connected across one diagonal, while a null detector is connected across the other diagonal. https://www.nvistech.com/product/experimentation-with-de-sautys-and-schearing-bridge/