SQUARE WAVEFORM FOR CALIBRATION: UNCERTAINTY ANALYSIS

Abstract: On the market are available many data acquisition systems not specifically designed for measurement application. When used for this particular purpose, although the digital stage would be adequate, the analog front-end is often source of unacceptable uncertainty. A new opportunity offered by modern powerful digital processor hosted on data acquisition systems consist in employing the processor for identify and compensate the non-ideal behavior of the analog front-end in real-time. The effectiveness of this method is greatly conditioned by the accuracy that can be achieved in the identification of the analog stage transfer function. This paper aims to investigate the effect of uncertainty in the test signal generator used to produce well-tailored stimula for the identification process. The use of a square waveform as a test signal has been investigated. This signal can be easily generated by the acquisition system itself, at low cost, with a proper accuracy level