3. Measurement recommendations

3.1 Planning, object handling, measurement positioning

Each participant was given a 5-week slot in which to take measurements of a mirror. Mirrors were exchanged between participants independently of each other.

Objects had to be handled by experts, preferably in areas with controlled dust and humidity levels. Gloves had to be worn when handling the objects.

To facilitate analysis of the results, it was important to manage the fiducialization of the objects to be measured. Indeed, it is important to identify the positioning and orientation of the object in relation to the measuring instrument when applying translation and/or rotation methods to the mirror to be measured, so as to be able to readjust the data in relation to each other....