A practical methodology for estimating uncertainty in electrical signal measurements

A practical methodology for quantifying electrical signal measurement uncertainty is presented. This approach allows the user to estimate the uncertainty of test equipment based on comparative measurements with off-the-shelf reference meters. By making a series of steady-state measurements with the device under test (DUT) and the reference meter connected in parallel, data which represents both the random and systematic uncertainties of the DUT can be obtained. The total measurement uncertainty of the DUT is then calculated using either quadrature or algebraic summation of the measured data for the DUT with the measured and published data for the reference meter. The resulting calculated uncertainty can be easily adjusted to the desired confidence level. A brief mathematical justification for this methodology is presented as well as an illustrative example