Using mathcad to simplify uncertainty computations in a laboratory course



Numeric experimental results are completely specified when accompanied by a quantitative magnitude of its uncertainty. Mechanical Engineering (ME) students at The University of Texas at Tyler, and in most of the ME programs, are introduced to experimental uncertainty through laboratory courses. In both laboratory activities and experiments, for variables not measured, results are obtained with the use of a data reduction equation (DRE). The DRE defines the relationship between the result of unmeasured variables and the measured variables, which is also used to estimate the uncertainty of the result (the unmeasured variable). The uncertainty of the result is estimated by applying a propagation of uncertainty approach that requires the implementation of partial derivatives on the DRE. If the DRE is complicated, the partial derivatives are quite difficult to perform. Therefore, Mathcad can be used as a tool to simplify the computations needed to estimate uncertainties. This paper illustrates the use of Mathcad to perform and simplify uncertainty computations for college laboratory activities and experiments. © 2014 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:250–257, 2015; View this article online at; DOI 10.1002/cae.21593