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Click on the images to enlarge​

This type of non-contact profilometry utilises white light axial chromatism technology which measures height directly from the detection of the wavelength that hits the surface of the sample in focus.  3D non-contact profilometry provides a full 3D image allowing a complete understanding of surface topography.

In this project a Nanovea ST400 Optical Profilometer was used to produce 3D images of a replicated surface pit.  The images produced were used to provide accurate pit depth information.

Pit type defects were intentionally introduced to mimic in-service defects found in pipelines commonly used in the oil and gas industries.  The individual defect depths ranged from ~7-15mm.  The defects were replicated at the client’s site using a high resolution Microset replication compound and profiled in ESR Technology’s laboratory. 

An optical pen providing a maximum of 20mm vertical Z height measurement was used to scan the replica surface.  The full 3D image of an example defect shows the level of detail provided for understanding the topography, coverage area, roughness and depth/height.  The software provided with the Profilometer allows for almost endless surface parameters to be calculated from the 3D scan; in the case of this project, the step height measurement function was used to yield detailed height information. 

Once scanned, the software allows for the 3D image to be levelled removing any inherent tilt across the replica sample.  Once levelled the user can then utilise the form removal tool within the software to remove various types of mathematical forms from a samples surface; in this case removing the inherent curvature on the inside of the pipe where the defects were located. 

Once these effects have been reduced or removed the user can then select a suitable flat area adjacent to the raised defect to act as the datum.  The simple step height measurement function allows for the height difference between the datum and the maximum measured defect height to be calculated yielding highly accurate defect depth/height information. 

For more information please contact Tim Gould on 01925 843450 or This email address is being protected from spambots. You need JavaScript enabled to view it..