Traditional process control for optical distortion involves periodic inspection using a flat bottom gauge. To evaluate a process with confidence, samples must be inspected at a frequency of one half the period of change in the process. This is the Nyquist theorem. If a process is stable and changes once in 60 minutes, samples should be measured every 30 minutes. If a process changes every load, every load should be measured. Glass toughening is a dynamic process involving variable such as glass thickness, type, coating, ambient atmospheric conditions and furnace wear. This paper looks at the measurement capabilities of LiteSentry - a new 3D system. Using patent pending optics, and machine vision technology, optical distortions are measured over the entire output conveyor bed of a toughening furnace. For more information see: www.litesentry.com
