Concave Convex Meter (0730)
Index: 0730
Year: ?
Maker: ?
Dimensions: 8 x 7 x 3 cm
Info
Tool for measuring the concave- or convexness of eg a lens by measuring the deviation of a pin against a calibrated circle surface.
The tool has 2 scales. The inner scale (dioptr ?) reads from 0 (flat surface) to 20 ascending. The outer scale from 80 (but center could be infinity) to 2 descending.