Estimation of Uncertainties in Indirect Multiparameter Measurements of Correlated Quantities

The paper presents an upgraded version of the vector method of evaluation of multiparameter measurement uncertainties stated in the Supplement 2 to GUM guide. This was done on the example of two-parameter jointed measurements. It consists of the correlation of individual components of the type A and/or type B uncertainty of input measurands. The general formulas for the covariance matrix, final uncertainties, and correlation coefficient were determined. The 3D graph shows the correlation coefficients of the output quantities as a function of the type B contributions in the uncertainty of two input quantities. It has been demonstrated that the inclusion of correlations of uncertainty components makes the uncertainty evaluations more reliable and accurate.