Local regression: a new approach for measurement system comparison analysis.

A new graphical approach for analysis of measurement system comparison studies is proposed. Unlike the established linear regression and Bland-Altman analysis, it does not depend on the assumption of a linear relationship. We review the established analysis approaches and propose a difference plot with non-parametric regression as an adequate tool to describe the relationship between two measurement systems. Along with pre-defined level-dependent acceptance limits, this approach may provide evidence for metrological equivalence between two measurement systems. Several data examples are given to illustrate this approach.