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Fixtures and Accessories

Bristol’s Optical Thickness Gauge systems can be configured with a variety of sample mounting fixtures and accessories, which ensure easy alignment to simplify the measuring process.

5-Axis Fixture

For optimal instrument performance, it is important that your sample is normal to the optical axis of the Thickness Gauge’s incident beam. The 5-Axis Fixture provides an easy way to position your material with X, Y and Z linear stages. Additionally, alignment of your material to the optical probe is controlled by the Pan and Tilt stages.


Group Index Measuring Cell

Our Thickness Gauge systems measure the optical thickness of the material and then convert this value to a physical thickness. This conversion requires you to know the Group Refractive Index value of each layer. Our Opti-Cal™ software includes an expansive library of Group Index values for many common types of glass and plastics. If the Group Index of your material is not known, it can be determined.

For more information on Group Index, why it is important, and how a Group Index Measuring Cell functions, please consult our Technical Note.