BS 7172:1989

This standard BS 7172:1989 Guide to assessment of position, size and departure from nominal form of geometric features is classified in these ICS categories:

• 35.080 Software

This British Standard provides information and guidance to manufacturers of coordinate measuring machines (CMMs), and particularly software writers within the CMM industry. It contains recommendations for determining the position, size and departure from nominal form of geometric features, given measurements of coordinates of points on a workpiece. The features covered correspond to the following geometric elements: lines, planes, circles, spheres, cylinders and cones.

This standard is concerned with software implementations of algorithms based on sound mathematical and computational principles, rather than automated versions of manual or graphical assessment procedures.

This standard does not provide detailed guidance on methods for treating data gathered in an unstable environment.

This standard does not cover secondary attributes, i.e. measures derived from departures from form of the above geometric elements, such as parallelism, concentricity or orthogonality.

This standard primarily relates to CMMs that operate with a right-handed Cartesian coordinate system. It also relates to other measurement systems that provide such coordinates. Some of the guidance provided also applies to other coordinate systems.

For manufacturers of coordinate measuring machines (CMM's) and software writers within the CMM industry. To promote better use of CMM's for assessment of geometric form.