Uncertainty contribution of the analog conditioning block in DSP-based instruments

The type-B evaluation of the uncertainty affecting the measurement provided by any instrument could be done by properly processing the nominal accuracy specifications of each functional block in the instrument. In DSP-based measurements, the implementation of such a procedure must face the difficulty arising from the fact that the parameters characterizing the accuracy of the input analog block are defined in the continuous-time domain. In this paper, a calibration procedure is proposed to tackle this issue. It is based on the use of high-accuracy data acquisition boards and the simultaneous acquisition of the signals at the input amid output of the analog block. The results of the calibration of active voltage transducers are reported. An application example is also developed and its results are discussed