.. include:: ../substitutions.txt

.. _vertical_sample_preparation:
    
Sample preparation for the Vertical Optical Dilatometer 
==============================================================

The optical dilatometer frames two opposite sides of the sample with two independent optics. 

In order to achive the best focus the sample should be:
    
    * machined with a triangular tip, in such a way that the length of the upper face parallel to the optical path is minimized
    * the long side of the sample should face the optics and be aligned with the holding plate