Optical Coherence Scanning Measurement Limit Boundaries on Vertical Tooling Cavity Sidewalls
Side-viewing prisms and polarized optical coherence gating extend sidewall slope scanning limits beyond eighty-five degrees in deep tooling cavities.
Spatial Frequency Resolution
Meaning
Metric defining the ability of a surface metrology system to detect and distinguish closely spaced topographic features on a moulded part. While vertical resolution measures the height of a texture, spatial frequency resolution determines how fine a pattern the sensor can resolve across the horizontal plane. This value is limited by the sampling interval of the detector and the size of the probe tip or optical spot.
A system with poor lateral resolution might record a rough surface as smooth because it cannot enter the narrow valleys of the texture.
Texture Detail
Fine matte finishes on automotive interiors require high lateral precision to ensure consistency between different tool cavities. The spatial frequency resolution of the inspection tool dictates whether micro-cracks or subtle tool marks are visible in the data.
Quality Standard
Specifications for optical components often include a limit on high-frequency ripples that cause light scattering. If the spatial frequency resolution is too low, the measurement will smooth over these defects and report a false pass for a part that fails in service.
Process Control
Monitoring the wear of a textured mold requires tracking changes in the sharp peaks of the grain. As the tool erodes, the measured spatial frequency shifts toward lower values, indicating a loss of definition that necessitates tool maintenance.