Metrology: How To Measure Complex Geometries

Cpap mask and scans

Take a CPAP mask for example – it seems pretty basic in appearance… 

However, when it comes to assessing a CPAP mask from a measurement perspective – it proves to be very complex. In metrology, traditional measurement tools such as CMMs and Laser Scanners, are simply ineffective. Neither can successfully measure flexible, transparent, and/or complex objects. 

Since CMM relies on a touch probe contacting the surface, consequently it will deform the object producing erroneous results. Further more, CMM also has issues dealing with inaccessible features due to the geometry of the object.  

Laser and light scanners cannot measure transparent objects without the addition of a surface coating. Therefore, these measurement tools also struggle with items featuring complex geometry when line of sight to the object feature is not available.  

The solution to accurately measure a CPAP mask – or any other object that’s flexible, transparent, and/or has complex geometry – is X-ray Computed Tomography (CT). This measurement choice is ideal for a number of reasons. CT does not apply any force to the object. It is unaffected by transparent or shinny surfaces; and collects internal and external data all within the same scan. In addition, internal as well as external geometry features, such as wall thickness, can be measured even if there’s no physical access to the internal structure of the object. Viola!  

We have a variety of X-ray systems on-site to quickly, easily, and cost effectively produce successful NDT and metrology results for customers nationwide. We’ve seen a multitude of different objects from numerous industry sectors come in to our Inspection Services Department for x-ray inspection and metrology. Some are simple jobs and some are complex. We love a challenge, so be sure to contact us when you need help.  

To learn more about our CT inspection services, our other X-ray capabilities, or to book a project – just give us a call at 763-447-4187 or email 

Share with a Friend