Spatial Analyzer is a points based software. Each point is traceable back to the instrument that measured it and that link is fundamental to geometry fitting and instrument alignment. SA has always made it easy to measure points and fit geometry to those points, analyzing the deviations and reporting the statistics. However, part inspection is all about streamlined comparisons between nominal and measured geometry, reporting measured locations within specified tolerances and effectively reporting those results.
SA uses Geometry Relationships to effectively link nominal and measured geometry position and location information, and dynamically update and report on these comparisons. These features can be built in advance or after measurements are made and, once built, provide a template for future measurements.
Geometry can also be inspected using our ASME and ISO compliant Standardized GD&T inspection process. The datums and feature checks will also appear as stand along inspection features that also will updated dynamically.
The primary reason these evaluation processes are separate in SA are:
GD&T feature checks use the built in datum references to perform an internal alignment and then evaluate with respect to that alignment. GR features display deviations using the current job alignment which provide greater visual feedback.
GD&T feature use either ASME or ISO inspection processes that are designed to establish if a part is within specification. This means that it optimizes fits using bounding thresholds in its mathematical evaluation. GR features use an RMS fit to help identify measurement error.
Although these are separate approaches, both GR-feature inspection and GD&T can be used in tandem. More information on GD&T features and inspection can be found in the chapter on “Verify Mode provides feedback during the inspection process.” on page 510. But the GD&T Datums and Feature Checks will appear as part of the inspection process which can be conducted through the Inspection bar just like GR features.