Measurement method of spherical large curvature radius

This paper introduces a precision measurement method to obtain the radius of curvature between 1m ~ 5m. With the laser beam irradiating the surface of the measured sphere, translating it in order to achieve amounts of the changing of the reflection angle of the laser beam at different locations in the surface of the sphere, and obtain the value of the curvature radius of the sphere. Repeating to Measure different points of the sphere can eliminate the random error factors on the measurement results. Application of this measurement method, for the sphere with curvature radius in the 1m ~ 5m and diameter greater than 100mm, the measurement error ΔR / R is in the 2×10 -5 ~ 10 -4 or less. This method has high accuracy, and can be used to measure the curvature radius of both concave and convex surface.