Bayer Kit
The optical field uses a modified version of the Oscillating Abrasion (Sand) tester to evaluate the abrasion resistance of lenses.
The Bayer Test consists of comparing the abrasion generated on a test specimen against an ISO Reference Lens (uncoated CR-39® lens). Both lenses are mounted in a special Bayer test lens holder that allows the curvature of the lenses to protrude above the bottom of the tray. After the specimens are covered with the abrasive media Alundum®, the tray is reciprocated in a back-and-forth (to-and-fro) motion a distance of 4 inches, at 150 cycles per minute for 4 minutes. Following the test the abrasion of the two lenses are compared.
The degree of abrasion is measured by the amount of change in haze as measured by a hazemeter. A ratio that compares the increase in haze of the test lens to that of the ISO Reference Lens provides a measure of how much more abrasion resistant the test lens is compared to an uncoated lens.
