Uncertainty analysis of cylindricity measurements using bootstrap method

This paper describes a method for performing uncertainty analysis of cylindricity measurements using bootstrap techniques. Errors in the Talyrond roundness measuring machine were studied and a variation was assigned to the roundness (r, θ) as well as the centerline position of the z-axis. The roundness data was dominated by an error that we characterized by a normal distribution with some standard deviation derived from repeated traces of the chosen artifact. The z-axis position error was also studied to provide a suitable distribution for these errors. A dataset was taken on the test artifact. Bootstrap datasets were produced from the original dataset and were analyzed using MATLAB. Uncertainty interval was determined from the cylindricity values obtained from the software. The uncertainty for the system was found to be ±0.092 μm with 95% confidence level. Effects of noise and straightness error on cylindricity value were also studied.