A high precision non-contact gauge for distance measurement

This thesis describes the development and evaluation of an experimental non-contact laser distance measuring device. The experimental gauge was based on the principle of triangulation, the high precision being derived from the combination of a stable method of generating converging beams and an accurate method of detecting their position using digital image processing. The experimental gauge was constructed and a 99% confidence interval for the error in ranging of 2.3)am was achieved for a gauge with a standoff of 60mm and a depth of field of greater then 20mm. The measurement of thickness of paint coating in a continuous process is examined as a potential application for this gauge.