Filtered Profile
The profile representation after passing through a filter. This can also be termed as 'modified data' and is different from raw or measured data because it has been adjusted or modified in some way by filtering or form removal etc.
Flatness
Flatness can be analysed by quantifying deviations from a least squares reference plane. A least squares reference plane is a plane where the areas above and below the plane are equal and are kept to a minimum separation. Flatness is calculated as the highest peak to valley normal to this reference plane.
Flatness can also be analysed by a minimum zone calculation, defined as two parallel planes that totally enclose the data and are kept to minimum separation. The flatness error can be defined as the separation of the two planes.
Form
The overall ‘shape’ of the object under test.
Form Analysis
The calculation carried out in the software which creates a form fit. For example, if a bearing is to be measured that is designed to be a true arc, it is possible to fit a best fit arc to the data in order to assess the deviations from it. It is the variation between this form fit and the real profile which enables form parameters to be calculated.
There are many types of form analysis based on measuring and comparing the actual form to the desired form.
Form Fit Exclude
Marking of those parts of a profile displayed in Data Selection View which are not to be used in calculation of the form fit. For example as ‘hole’ in the surface profile.
