Definition The tolerance zone is limited in the measuring plane wich is perpendicular to the axis by two concentric circles a distance t apart.
The toleranced circumference shall be contained whithin the tolerance zone in any angular sector starting from the profile centre and featuring any width.
Example
The “local“ roundness deviation shall
be smaller than 0.012 in any angular
sector starting from the profile center
and featuring a width of 15°.
Note
The roundness deviation as per ISO 1101 may be larger; if necessary, it can be toleranced separately.