You can see beside our chemist preparing solutions for quantitative analyses.
Raw materials have to compell to internal specifications; all of these are tested statistically on different sampling intervals according to quantity and reliability of the suppliers. Despite, each batch (one day production of a single furnace) of feed powder is systematically controlled:
1°) for physical properties such as moisture content and flowability
2°) chemically for impurity and dopant concentrations using ICP
3°) Verneuil production qualification Only then can a batch of feed powder be transferred in one of our Verneuil equipment
You can see here under a boule being immersed in a liquid for laser internal defect examination.
Every single boule produced by RSA is measured: 1°) For external quality and dimensions using a high speed digital camera linked to our database via an image analysis software.
2°) For internal quality with a high power laser scanning the boule making use of the Tyndall effect. A high refractive index liquid ensures a good signal to noise ratio. Also linked to our database, this semi-automatic equipment gradually replaces the manual one.
The boules are then annealed in batches before sales