Determination of the pressure coefficients of electronic voltage standards

Abstract

Electronic voltage standards (EVSs), based on Zener-diode reference elements, are widely used as standards to maintain a local representation of the voltage unit and as transfer standards for comparisons between local voltage reference standards at different locations. In order to make optimum use of such standards, it is important that individual units be characterised for the effects of external influence factors so that the appropriate corrections can be applied. Ambient atmospheric pressure affects the outputs of some EVSs. An experimental set-up to measure the pressure coefficient of an EVS is described and data showing the correlation between pressure and output voltage presented. Pressure coefficients calculated for the 10 V outputs of a range of commercial electronic voltage standards are also presented.