Meaning
Surface measurement technology combines the small depth of field of an optical system with vertical scanning to generate detailed topographic maps. Utilizing focus variation metrology allows for the analysis of both form and roughness on complex engineering components. The system captures multiple images at different heights and uses the sharpest pixels to calculate the three-dimensional coordinates of the surface.
It is particularly effective for measuring steep flanks and rough textures.
Vertical Depth
Scanning the sensor through a range of heights provides the data necessary to reconstruct the part geometry. In focus variation metrology, the depth of field is intentionally kept small to increase the precision of the focus detection algorithm. This allows the system to measure parts with high vertical relief that would be difficult for other optical methods.
Surface Analysis
Software algorithms process the captured light intensity to determine the texture and color of the specimen. Because focus variation metrology is based on the contrast of the surface, it works best on materials with some level of natural roughness or grain. Polished or mirror-like surfaces may require special lighting or a fine coating to be measured accurately.
Resolution Quality
Detailed inspections of micro-tools and molded parts rely on the high spatial resolution of the optics. Focus variation metrology can detect small defects or wear patterns that are invisible to the naked eye. This data is used to verify that tooling is performing to the original design specifications during long production runs.
