Make sure automated machinery is programmed and running properly.
Tends electric oven-type machine that hardens lenses used in safety eyeglasses, and tests hardness of lens, using steel-ball drop-test: Measures lens thickness with calipers to determine if lens meets thickness requirements for prescribed hardening. Positions lenses in holding fixture and pushes fixture into electric oven. Sets timer and temperature controls on oven according to chart specifications for prescribed hardness of lens. Removes lenses at end of cooling cycle, or places lenses in airflow to cool. Holds finished lens in polarized light fixture to detect defects produced by hardening. Places lens on bed of drop-test fixture and covers lens with cloth or plastic. Places steel ball of specified weight in release mechanism of fixture. Positions mechanism at specified distance from lens and releases ball. Discards broken lenses.