6. Conclusion

Wheatstone bridges are widely used for impedance comparison in both metrology and industrial applications. The use of real bridges, however, requires a number of tricks to ensure that their behavior conforms to theoretical models. Transformer bridges are also frequently used, as quality transformers are precise and relatively inexpensive tools. The search for very small uncertainties or the need to increase frequency may lead to the use of bridges with a coaxial structure, implying a better definition of the notion of impedance and compliance with very precise measurement conditions. Whatever the type of bridge chosen, the finesse with which equilibrium can be achieved is crucial. Synchronous detectors are the most suitable tools for achieving this fine balance. The frequency at which you wish to operate, the sensitivity required and the price are the main criteria on which the choice of...