3D Inspection of the Inside of a Part

Manufacturers who use a 3D scanner in their quality inspection processes sometimes need to inspect the inside of a part. In such situations, 3D scanners are used along side CT scanners.


3D model of plastic bottle, based on 3D scan data provided by ShapeGrabber, showing cross-sections that will be measured.

A 3D laser scanner like a ShapeGrabber scanner can provide fast, accurate and radiation-free scanning of the complete external surface of a part, no matter how complex its shape. The 3D scan data can then be analysed using graphical tools such as color mapping and whisker plots, or more traditional methods such as cross-sectioning and point to point dimensioning, to obtain accurate measurements of the part.

However, no 3D laser scanner can measure the inside of a part without cutting the part to access those features. X-ray computed tomography, also known as CT scanning, can be used in conjunction with a 3D scanner when internal inspection is necessary, and it is not possible to cut the part.

Both 3D scanners and CT scanners provide non-contact
scanning. The difference is that CT scanning employs x-ray technology to capture interior features of parts, including complex or free-form shapes.

These two types of scanner are often used in complement and do not replace each others’ function. For surface-scan applications where speed and accuracy are paramount, a 3D laser scanner is ideal. When internal inspection is the priority, and one is willing to compromise on speed, a CT scanner is the right choice. CT scanner operation may require  protective radiation gear (and safety training), while laser scanning has no such considerations.

Cross-section data – plastic bottle.

Every type of 3D scanner has optimal applications and uses. Talk to ShapeGrabber about your specific inspection and measurement needs. We’ll be happy to advise you about whether a 3D laser scanner can be integrated into your quality inspection process.