Sensitivity Error in Frequency Measurements with the Wien Bridge

Abstract

The limitation in the null instrument sensitivity of bridges leads to errors which are due to the uncertainty in the null adjustment. This paper deals with this sensitivity error in Wien frequency bridges. Formulas for the relative error in frequency measurement and for optimum bridge parameters are derived. The influence of deviations from the optimum parameters is shown and discussed. It is shown that, for bridges covering a wide frequency range, certain free parameters should be made adjustable to maintain good sensitivity.