(under subclass 649) Subject matter wherein a light beam is employed which is modified in accordance with the vibrations in order to obtain an indication or measurement.
(1) Note. Measurement of a modification in the direction or intensity of the light beam is included in this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
653, for similar structure in combination with inertia type sensing apparatus.
SEE OR SEARCH CLASS
356, Optics: Measuring and Testing,
445+, for optical measuring and testing involving interferometry.
