Non-contact thickness measurement
STIL chromatic confocal sensors are designed to measure thicknesses without contact, by transparency or by step height difference and face-to-face, in all environments such as in-line industries or laboratories.
The principle consists in measuring the position of a diopter, i.e. the interface between two surfaces of different refractive index, and, simultaneously, the position of another diopter.
The difference between the two distance measurements indicates the optical thickness measurement, from which the mechanical thickness is deduced.
The measurement of samples comprising several layers is possible using the same method: the multi-layer measurement software is available on some STIL controllers.
- High axial resolution: From nanometer scale (nm)
- High lateral resolution: From micrometer scale (µm)
- Optical heads only composed of passive components
- High signal to noise ratio
- Works on a large set of materials, including black carbon, glass, colored or white ceramic & plastics, rough or polished metal
- Wide choice of measuring ranges
- Steep slope compatibility thanks to Large Numerical Aperture (NA)
- Coaxial (no shadow effect)
- « Speckle » free
STIL sensors are composed of several references, from one measuring point to multiple measuring points distributed along a line or in a field.
ChromaPoint optical heads are interchangeable to guarantee flexibility, reliability and adaptability in any kind of application and on any surface reflectivity: transparent, opaque, diffusing, shining.
For transparent samples such as glass, the minimum thickness measurement and specifications considering the path through a surface with a refractive index n=1.5 are given in the data sheet.
Similarly, the maximum thickness of a transparent sample such as glass is to be considered according to the refractive index.