Optical metrology

Micro & Nanopositioners

Microscopy products

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Measure thickness of glass or transparent objects


The OEG CAS is a sensor device allowing accurate measurement of distance and thickness of glass.

The measuring head includes a laser projection lens, an objective measurement and a miniature CCD camera with 440,000 pixels.

The standard version of CAS-30/30 uses a beam symmetrically. The optical axes of the projection lens and the objective of measuring an angle of 30 ° from the normal to the surface of the sample.

A shift of the sample under test along the z axis induces a shift of the spot on the CCD camera. This displacement is measured with a resolution better than the pixel using a system of image processing. A calibration system for high precision allows a resolution of 0.1µm with a working distance of 22 ± 0.5mm

Sensor specifications CAS-30/30

  • Size : 155X55X145mm
  • Mass : 400g
  • Working distance : 22 ± 5 mm
  • Extern power supply 5V et 12V ( DC )
  • Time to measure: between 0.1s and 0.5s depending on the configuration used
Polished surfaces
Unpolished surfaces
Accuracy for a measuring range of 100µm


Accuracy over the entire measuring range


Measurement Range
800µm ±400µm
600µm ±300µm

(*) These parameters relate to standard equipment and can be adapted to all specific applications

Online documentation:

Download the brochure CAS (sensor only)

Download the brochure EHD (Bench for measuring the uniformity of thickness)

Download the brochure WMT (Bench for measuring wafer thickness)

Download the brochure GPM (Bench to characterize large samples)

Link to the website of the company OEG

If you would like more information, please contact us.


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