Part to CAD / Nominal - CT Scanning Services
Part Inspection Lab

We help companies quickly identify part deviations from the CAD / Nominal
model using our Metrology based
CT scanning services

Part to CAD

Most of our clients identify internal imaging with a personal experience in the medical industry.  However, contrary to popular belief our CT Scan services are found to be highly beneficial for inspection of industrial parts and assemblies.

Our advanced Industrial (Computed Tomography) CT Scanning services are able to aid manufacturers when inspecting difficult to measure part features with micro measurement variations from the design intent.  



After a part is scanned, a supplied CAD model from the customer is compared to the scan dataset. Alignment is performed by either a best fit method or predetermined datum’s. Results are supplied in a color coded model showing deviations from CAD for both internal and external geometry.

In addition to the 3D color coded model, 2D whisker plots are also included with the results to show deviations in cross sectional slices between the scanned part and CAD model.


  • Results show differences between identical parts manufactured from locations, processes, or tool cavities.


  • Results show internal and external differences between the part and CAD model
  • Results can show differences in 2D cross sectional slices and in 3D.

Need more info on part to
cad / nominal comparisons?
Review our knowledge section below.

With the Nominal/Actual Comparison add-on module, VGStudio MAX provides a unique tool for the direct comparison of volume data with a CAD model or a second volume data set. Having used the Coordinate Measurement add-on module to fit the CT data set to the nominal CAD model, oversize and undersize is determined over the entire surface.


The data set to be examined is color-coded according to its deviation from the specification and a report containing statistical data as well as 2D and 3D images of the critical areas is generated. Since Nominal/Actual comparisons are performed directly on the volume data sets, there is no need to convert volume data into a surface model, which is not only time-consuming but also results in a loss of data. A ROI (Region of Interest) concept allows comparisons to be restricted to specific areas of an object


  • automatic and fast comparison of a scanned object with a reference object
  • comparison of volume data with a CAD model (Nominal/Actual Comparison) or a second volume data set (Actual/Actual Comparison)
  • color-coded visualization of analysis results
  • direct comparison of volume data sets – no conversion to point clouds or STL data required
  • user-defined reporting of all analysis results
Nominal/Actual Comparison*

Get an easy-to-understand visualization of deviations of your scanned object from a reference data set.

The nominal/actual comparison features:

  • Give you a color-coded comparison between voxel, CAD, and mesh data (also referred to as false color plot).
  • Allow you to position annotations individually, tolerate them, and place min./ max. information automatically.
  • Statistically analyze a full part or rule-based created components.
  • Have an adjustable color bar for smooth or stepped color transitions and transparent areas.
  • Offer hairline rendering in 2D slices.

Interested in accessing our services for
helping you and your company?