Crosstalk Effects in the Uncertainty Estimation of Multiplexed Data Acquisition Systems

This article deals with the analysis of multichannel data-acquisition systems with the aim of identifying and combining the main uncertainty contributions according to the guide to the expression of uncertainty in measurement (GUM) framework. Particular attention has been paid toward crosstalk effect, which could be an important uncertainty contribution in multiplexed data-acquisition systems. The uncertainty analysis is described for three commercial data acquisition devices highlighting that crosstalk specifications are often not suitable for reliable uncertainty estimation in operating conditions. For this reason, an experimental setup has been arranged to fully characterize the interchannel effects of the investigated devices. The obtained results have highlighted that proper characterization of a data-acquisition system is effective in estimating the actual performance at the frequency of interest and in the operating conditions for the source resistance and the input-channel configuration. Eventually, a customized procedure has been proposed, which is effective in correcting the crosstalk effects also in very severe conditions of interchannel disturbance.