Optical Coherence Measurement Fundamentals for Deep Tooling Cavities
Optical coherence measurement uses broad-bandwidth infrared interference to capture deep cavity topographies without mechanical probe contact or lens clipping.
Micro Stylus CMM
Meaning
Dimensional metrology tool using a small diameter probe to measure high precision features on a microscopic scale. The use of a micro stylus cmm is essential for verifying the geometry of micro molded components such as gear teeth or medical filters. It measures features that are too small for standard ruby tips or too complex for optical systems alone.
Contact Precision
Small parts often have vertical walls or deep cavities that light cannot reach. A micro stylus cmm utilizes tips with diameters as small as 25 microns to touch these internal surfaces. This physical contact provides a 3D map that is unaffected by the transparency or color of the resin.
Deflection Mitigation
Probing forces must remain extremely low to avoid deforming soft polymer parts during the measurement cycle. Modern micro stylus cmm technology employs ultra sensitive sensors that trigger at millinewton levels of pressure. This prevents the probe from digging into the plastic surface and generating false readings.
Calibration routines account for the flex in the thin shaft of the stylus. Environmental controls limit the thermal expansion of the granite base. Vibration isolation protects the sensitive bridge from floor movements.
Feature Verification
High cavitation molds produce parts that must be identical across all gates. Using a micro stylus cmm ensures that the critical dimensions of every cavity meet the tolerance specification.