Optical Force Gage
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
An optical force gage is provided in which the force applied to a cantilever beam produces a proportional difference in the principal strains on two birefringent coated areaa of the beam. The figure shows, schematically, the elements of the present embodiment, in which a cantilever beam 1 is coated with a birefringent material in two areas 2 and 3. Light rays from two sources 4 and 5 impinge on areas 2 and 3 and are reflected to photo cells 6 and 7, respectively, which normally produce equal outputs. Light sources 4 and 5 may produce infrared, visible or ultraviolet radiation. Both principal and reflected light rays are controlled by the optics 20 of dual-reflection polariscope systems. The reflected rays are further controlled by servo stepper motor-driven null-balance compensators 10 and 11.