Sunglasses detection methods: comparative analysis of the measuring methods of dioptric power

Sunglasses are introduced in this paper detection methods of comparative analysis of the measuring methods of dioptric power. 1. Telescope method method using fewer in China. In the measurement of large size or bending larger samples more convenient; In addition, when measuring transmission low sunglasses will not be affected. But the telescope method cannot be ignored at the same time there is the following disadvantages: subjective error sentence degrees; Repetition can not correctly after the light source under the condition of top coke to measure; The lack of calibration methods; Measuring the amount of life of luminosity, especially with column lens degree of lens there is principle error. 2. Focal viscometer method focal meter method is commonly used detection methods in China. With convenient, fast, autofocus, reading high resolution; Can be measured flat, the mirror with photometric especially with column lens; The advantages of the measuring principle in accordance with the ISO definition. Focal meter in the measurement of transmission, however, lower colored sunglasses, the measurement unstable; For large camber of flat lens positioning; Zero value for lack of calibration methods, different type instruments such as lack of comparability between the shortcomings and the insufficiency. Specific as follows: A. Zero calibration. Focal viscometer method of measurement process is relatively simple, but its top coke at zero value for lack of calibration, resulting in different focal meter on the measurement results of the same sample of divergence. B。 Transmission ratio. Focal meter in the measurement of transmission with low color sunglasses, there will be a value for instability, reading difficulties. C。 Big curvature sunglasses. Focal meter in the measurement of large surface curvature sunglasses due to location difficulty measurement error is bigger.