The Optical Micrometer is capable of making non-contact measurements on any surface, curved or flat.  This instrument is useful for measuring depth of scratches, fractures, crazing, embedded voids and thickness of transparent materials (i.e. glass, acrylic). It can also measure scratches, cracks, corrosion, pits, blemishes, small dents and other imperfections.  Using the optional reticle eyepiece on Model 966A, width measurements up to 0.040" can be made.