Getting The Right R^sub z^

摘要

In the case of R^sub z^, the situation is particularly complex because it Is one of the oldest surface finish parameters. Unlike R^sub a^, or average roughness, which considers all the peaks and valleys in a sample, R^sub z^ typically looks at only the five highest and five lowest points in a sampling length and averages peak-to-valley distances. Thus, many users consider R^sub z^ more sensitive to actual changes in surface finish than R^sub a^.