Lay
Many machined surfaces will have a distinct directional characteristic which is called a lay. Lay refers to the predominant direction of the surface texture. Ordinarily lay is determined by the particular production method and geometry used.
Surfaces having a directional lay are called anisotropic while those without a predominant lay direction are isotropic. It is sometimes necessary, if the lay is functionally important, to specify on drawings the direction or type of lay. For example, a turned cylinder will have a lay that is at right angles to its axis.
Lc Cut-off
The Lc Cut-off specifies the high pass cut-off length for the selected filter. Wavelengths around and greater than this length will be removed or attenuated in amplitude by the filtering process.
See also Ls Cut-off and bandwidth
Least Squares Circle
The Least Squares Reference Circle is a circle where the sum of areas inside this circle are equal to the sum of the areas outside the circle and kept to a minimum separation.
Least Squares Cylinder
The least squares cylinder is constructed from the average radial departure of all the measured data from the least squares axis.
Least Squares Line
A least squares line is a line through a profile such that the sum of the squares of the deviations of the profile from the mean line are at a minimum.
The most common application of a least squares mean line is to "level" the measured profile by calculation rather than mechanical means.
Local Peak
A local peak is a region of a profile between two successive local valleys in the profile.
Local Valley
That part of a profile flanked by a peak on either side.
Ls Cut-off
The Ls Cut-off specifies the low pass cut-off length for the selected filter. Wavelengths around and less than this length will be removed or attenuated in amplitude by the filtering process.In a primary analysis, Ls is the only cut-off specified.
See also Lc Cut-off and bandwidth
