Alignment metrology

Abstract

Alignment measurements which have to be made on workpieces whose size allows them to be placed on a surface table do not in general present serious problems. The reason is that the table itself provides a flat reference plane and any line across the table provides a straight reference line (Fig. 3.1). 90° lines which are square to the plane or line are provided by L-type or box squares or cylindrical squares. Dial test indicators, height gauges, gauge blocks or even feeler gauges are used to make the actual measurements with respect to the plane, line or square.