CAN BE ESTIMATED THE MEASUREMENT UNCERTAINTY OF DAQ SYSTEM FROM DATA SHEETS OF USED A/D MODULES?

摘要

The estimation of a measurement uncertainty ofrna sampled signal based on parameters of A/D modulesrnpublished in data sheets is not already trivial. When a veryrnlow frequency (pseudo-static) signal is sampled, the staticrnparameters, which are usually published by well-knownrnproducers can be used for this purpose. The morerncomplicated situation arises in the case of a dynamicrnmeasurement, when the most of producers present onlyrnminimum of parameters. It is usually the total harmonicrndistortion (THD), or the analogue bandwidth for low and/orrnfull scale signal. The most important dynamic parameters asrnthe effective number of bits (ENOB), or the signal to noisernand distortion (SINAD) including their frequencyrndependence are published very seldom.