6212C Manual Version 15_22 Rev 07-19.docx
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Appendix A
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Lasercheck Alignment Principles and Procedures
This section contains information on principals and procedures to install and align Lasercheck heads. The keys to
getting accurate and repeatable data are controlling alignment and cleaning the surface.
How Does Lasercheck Work?
The visible (650-nm.) laser illuminates the surface with a shallow incident angle to measure surface roughness
features. The distribution of reflected and scattered light from the surface is detected by a photodiode array
with 35 small closely packed detectors. This relative distribution of reflected and scattered light is used to
calculate the surface roughness of the area illuminated by the laser beam. The array is also scanned by software
to find the specular beam (when there is one) and its position is used to determine height of the measurement
head from the surface.
The image shows a schematic of the layout of the laser, the beam path and the detectors in Lasercheck. The
“Photodiode Array” has 35 discrete detector elements.
Schematic Diagram of Lasercheck Instrument