Small-size measuring gauges for metal cutting machine tools

Recently two new models of suspension type optical measuring gauges have been developed with a 0.01 mm scale division, for measuring displacements of movable parts in metal cutting machine tools. The first one is the IG-98 consisting of an STs-80 incandescent lamp, a light filter, two reference rulers, two objectives, a light splitter cube, four plane mirrors, two condenser lenses, a graduated circle and a magnifying glass. The second one is the IG-119 consisting of an STs-61 incandescent lamp, a light filter, a rectangular prism with cover, two reference rulers, two objectives, a light splitter cube, one mirror, one condenser lens, a cylindrical shield and a magnifying glass. A complete accuracy analysis of both instruments indicates that two out of the seven principal error components are negligible, namely the angular error of the null adjustment guides and the temperature error referred to the plane of one of the reference rulers.