scope:

Scope and field of application

This International Standard specifies a method for determining departures from roundness by measuring variations in radius by means of contact (stylus) instruments.

It establishes

a) types of instruments and general requirements;

b) recommendations for the use of instruments;

c) procedures for calibration of instruments and verification of their characteristics.

This International Standard applies to the assessment of the departures from ideal roundness of a workpiece through the medium of a profile transformation, obtained under reference conditions, expressed with respect to any one of the following' centres

a) centre of the least squares circle;

b) centre of the minimum zone circle;

c) centre of the minimum circumscribed circle;

d) centre of the maximum inscribed circle. Each of these centres may have its own particular application. The position of the least squares centre can be calculated from a simple explicit equation given in annex F.

Departures from roundness of the measured profile, procedure, calibration and determination of systematic errors of rofation are dealt with in annexes A to D, respectively. Annex E gives rules for plotting and reading polar graphs.

NOTES

1 Profile transformation is defined in IS0 6318.

2 Reference conditions include the stylus, frequency limitations of an electric wave filter (if used), permissible eccentricity of the graphical or

digital representation of the profile (generally 7 % to 15 % of its mean radius, see annex E), the position of the measured section or sections relative to some feature of the workpiece.