1. View the surface and decide whether profile is periodic or non-periodic.
2. When the tolerance limit is specified, use the table shown on the left for condition.
3. When the tolerance limit is not specified.
3.1 Estimate roughness and measure it in corresponding condition in the table.
3.2 Change condition according with above result and measure it again.
3.3 Repeat “3.2” if the result does not reached the condition.
3.4 When the result reaches the condition, it will be the final value.
Check it in shorter sampling length at non-periodic and change it if it meets.
4. Compare the result toward tolerance limit in accordance with following rule,
Upper limit - the 16% rule (Default)
Measure on the most critical surface. If not more than 16% of all value based on sampling length are exceed the limit, surface is acceptable.
- The first value does not exceed 70% of the limit.
- The first three values do not exceed the limit.
- Not more than one of the first six value exceed the limit.
- Not more than two of the first twelve value exceed the limit.
or when μ+σ does not exceed the limit, the result is acceptable.
Lower limit - the 16% rule (shown as L)
Measure the surface that can be expected the lowest roughness.
If not more than 16% of all sampling length are less than the limit,
or when μ-σ is not less than the limit, the result is acceptable.
Max value - the max rule
(when “max” suffix is added)
The value is acceptable when none of value in entire surface is over the limit.
Height characterization using the material probability curve of ISO13565-3
Draw a material ratio curve on normal probability paper from the roughness profile 4(primary profile) of an evaluation length.
Separate the material probability curve to 2 area, upper plateau area and lower valley area.
Rpq（Ppq）-parameter: slope of a linear regression performed through the plateau region.
Rvq（Pvq）-parameter: slope of a linear regression performed through the valley region.
Rmq（Pmq）-parameter: relative material ratio at the plateau to valley intersection.
