Glass measurement with alpha.glass
Laser triangulation sensors can also be used for measuring panes of glass. alpha.glass type systems can be used for measuring the bending of double paned laminated safety glass of windscreens and rear wind-screens of cars.
For producing the curvature of the panes of glass these are moved into a kiln on a transport device and subjected to a defined spatial and temporal temperature profile. After this process the curvature is measured using three laser triangulation sensors along three paths while the glass is hot. Because of the structure of the layers of laminated panes, multiple reflections of the laser beam occur. The resulting disturbances of the measured data are eliminated by filter algorithms.
For a curvature of 13 mm fifty repeated measurements produce a standard deviation of the laser measuring system of < 10 micrometers. With a resulting cg value of 20, this enables a measuring system analysis under production conditions. The measuring system described here is used in the three-shift operation at several locations for quality control and for controlling the kiln process.