Surface Stress Meter

It adopts optical waveguide effect of the ion exchange layer on the glass surface to measure. The divergent light emitted from the light source passes through the slit and is converged by the high refractive index cylindrical prism and becomes parallel light. By adjusting the position of the light source, a beam of parallel light is incident on the interface between the glass and the prism at a critical angle. Due to the stress existing on the glass surface, the light is decomposed into two vector lights whose vibration planes are perpendicular to each other. The two beams of light propagate at different speeds in the ion exchange layer of the glass, so they are refracted to the prism at different total reflection angles. The light emitted from the prism is reflected by the mirror, enters the interference filter, is focused by the telescope system, and then passes through the analysis mirror and is imaged on the reticle to form a light and dark step image. The height of the steps and the number of step lines can be accurately measured through analysis software to calculate the surface stress intensity and the depth of the stress layer.