B6.2 - The Uncertainty of Roughness Parameters

Event
AMA Conferences 2013
2013-05-14 - 2013-05-16
Nürnberg
Band
Proceedings SENSOR 2013
Chapter
B6 - Dimensional Measurement
Author(s)
J. Seewig - Technical University of Kaiserslautern (Germany)
Pages
291 - 296
DOI
10.5162/sensor2013/B6.2
ISBN
978-3-9813484-3-9
Price
free

Abstract

The process capability is an important indicator for stable and reliable manufacturing processes. Hence, the measurement uncertainty and the unambiguous calculation of geometrical parameters play an important role in quality control. A major deficiency pertains to the evaluation of the uncertainty of surface roughness parameters. Already simple roughness parameters have a large statistical variance depending on the manufacturing process and not on the measuring system. For industrial companies it is essential to find rules to express the surface roughness uncertainty, particularly for geometrical tolerancing. By describing a surface parameter as a statistical variable, it will be shown that the uncertainty can be expressed more precisely than in usual practice. As an example, the rule of thumb “six times Ra is approximately Rz” is derived from a statistical model of the surface.

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