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.
Multi Bounce Optical Path
Meaning
Light propagation arrangement where a beam is reflected multiple times within a crystal or across a surface to increase the interaction length with a sample. In Fourier transform infrared spectroscopy, this technique allows for the detection of extremely thin layers of residues or coatings on a polymer surface. By increasing the number of reflections, the signal from trace contaminants is amplified enough to be clearly identified against the background noise.
Surface Sensitivity
Analysis of additives that have migrated to the exterior of a moulded part requires a shallow penetration depth to avoid measuring the bulk resin. The multi bounce optical path of an attenuated total reflectance crystal captures the chemical signature of the top few microns of the material.
Detection Limit
Weak signals from low-concentration surface treatments are strengthened as the beam travels through the interface several times. A system with a multi bounce optical path can identify silicon oil contamination that would cause paint adhesion failure even when the layer is only nanometers thick.
Analytical Precision
Consistent pressure between the sample and the crystal is necessary to ensure that the light couples effectively with the surface. This ensures that the resulting spectrum is a true representation of the surface chemistry rather than an artifact of poor contact.