The two planes must be nominally parallel. The FCF will use them internally to construct a mid-plane. This mid-plane must nominally lie within the tolerance zone about the locating datum.

PC-DMIS checks the "corner points" of the mid-plane to verify that they lie within a planar tolerance zone of two times the maximum deviation of the "corner points" from the locating datum.

These "corner points" are calculated by projecting the actual probe hits of each of the two planes onto the mid-plane.

1. • The maximum distance of the projected points from the centroid of the mid-plane in the X direction (of the datum reference frame) determines the "length" of the mid-plane.

   • The maximum distance of the projected points from the centroid of the mid-plane in the Y direction (of the datum reference frame) determines the "width" of the mid-plane.

The "length" and "width" calculate the corner points relative to the centroid of the mid-plane. If there are no actual probe hits to project (for example, the two planes are themselves constructed planes), then only the centroid of the mid-plane is checked to lie within the tolerance zone.

Datum Information

One Datum - This is a plane nominally coplanar with the constructed mid-plane. The vector of the datum plane defines the direction of measurement.

Two Datums - First datum: This is a plane nominally coplanar with the constructed mid-plane. Second datum: This is either a plane nominally coplanar with the constructed mid-plane or an axis type feature whose axis nominally lies in the constructed mid-plane. If a plane, the vector of the secondary datum plane determines the direction of measurement. If an axis type feature, "double-crossing" the vector of the axis datum with the mid-plane vector determines the direction of measurement.

The two lines must be nominally parallel. The FCF will use them internally to construct a mid-line. This mid-line must nominally lie within the tolerance zone about the locating datum.

PC-DMIS checks the "endpoints" of the mid-line to verify that they lie within the planar tolerance zone of two times the maximum deviation of the "endpoints" from the locating datum.

These "endpoints" are calculated by projecting the actual probe hits of the two lines onto the mid-line. The projected points farthest away from the centroid of the mid-line determine the "endpoints". If there are no actual probe hits to project (for example, the two lines are themselves constructed lines), then only the centroid of the mid-line is checked to lie within the tolerance zone.

Datum Information

One Datum - This datum is either a plane, nominally perpendicular to the plane of the two lines, that contains the mid-line, or an axis type feature whose axis nominally lies in the plane that is perpendicular to the plane of the two lines and contains the mid-line. If a plane, the vector of the datum plane determines the direction of measurement. If an axis type feature, the direction of measurement is perpendicular to the axis datum in the current workplane.

Two Datums - First Datum: A plane nominally perpendicular to the mid-line. Second Datum: This is either a plane feature or an axis feature which satisfies the same requirements as a single primary datum. If a plane, the vector of the plane determines the direction of measurement. If an axis type feature, the direction of measurement is perpendicular to the axis datum in the current workplane.

Datum Information

One Datum - This datum is either a datum plane which nominally contains the mid-line or an axis type feature whose axis nominally is parallel to the mid-line.

Two Datums - Primary Datum: This is a plane nominally perpendicular to the mid-line. Secondary Datum: This is either a plane or an axis feature which satisfies the same requirements as a single primary datum. The direction of measurement is determined the same way as for case 2 above.

Datum Information

One Datum: You can select either a plane or an axis type feature for your datum. If a plane, it should be nominally perpendicular to the line connecting the two points and containing the mid-point. The vector of the datum plane determines the direction of measurement. If an axis feature, it should lie in the plane perpendicular to the line connecting the two points and the mid-point. The direction of measurement is perpendicular to the axis datum in the current workplane.

Datum Information

One Datum: You can specify either a plane that nominally contains the mid-point or an axis type feature. PC-DMIS determines the direction of measurement in the way as case 4 above.

Datum Information

One Datum: You can specify a plane or an axis type feature. The analysis in this case is the same as for the legacy symmetry dimension.

PC-DMIS will compute mid-points from the points inside the two sets in this fashion: mid-point n is calculated from point n of the first set and point n of the second set and so on for each point. The resulting mid-points should be inside the planar tolerance zone about the locating datum. This is the same analysis as case 7 above except that the points are taken from two sets.

Datum Information

One Datum: You can specify a plane or an axis type feature for the primary datum. The analysis in this is the same as described in case 7 above.

Probe points within 1 mm of a plane that is perpendicular to the feature axis belong to the same "circle set". PC-DMIS solves the points as a 2D circle in a plane perpendicular to the feature axis. The centroids of all the "circle sets" are evaluated for symmetry to see if they all lie within the tolerance zone about the datum. The tolerance zone may be cylindrical or planar depending on the datums used. The reported tolerance value is two times the maximum deviation of the centroids of the "circle sets" from the locating datum.

Datum Information

One Datum - You can select a plane that nominally contains the considered feature's axis or an axis type feature nominally coincident with the axis of the considered feature. If a plane, the tolerance zone is planar and the vector of the plane determines the direction of measurement. If an axis type feature, the tolerance zone is cylindrical.

Two Datums - Primary Datum: This is a plane nominally perpendicular to the considered feature. Secondary Datum: You can select either a plane nominally containing the considered feature’s axis or an axis type feature nominally coincident with the axis of the considered feature. If you choose a plane, the tolerance zone is planar, and the vector of the datum plane determines the direction of measurement. If you choose an axis type feature, the tolerance zone is cylindrical.

The endpoints must all lie within the tolerance zone about the locating datum. The tolerance zone may be cylindrical or planar depending on the datums used. The reported tolerance value shall be two times the maximum deviation of the endpoints from the locating datum.

Datum Information

This is the same as case 9 above.