(1) principle: simulate the light to irradiate on the horizontal convex surface of the lens to measure the light intensity of the fake Oakleys lens, and to determine the ability to prevent ultraviolet radiation.
(2) scheme: a normal sampling according to GB2828 and the use of general inspection level on batch production of lenses.
(3) step: 1. open the test chamber cover of the spectrum analyzer at room temperature, put the test lens in the clip, and close the lid.
1. The curve of the wavelength and transmittance of the tested Oakley knockoffs lens is obtained by the spectrum analyzer through the computer and printer.
Results: the transmittance of UVB 280nm-315nm: <0.1Tv and UVA 315NM-350nm:<0.5Tv. in this range is qualified, otherwise it is unqualified.
2. requirements for different uses
spectral transmittance ratio and traffic light identification are required for sunglasses used for driving. The requirements of special purpose glasses including light transmittance of photochromic glasses, gradient colored cheap Oakley sunglasses, polarized fake Oakley sunglasses are basically the same in all countries.
3. light intensity and prism degree
The light intensity is equal to the difference between the convergence of the square beam and the convergence of the square beam, which represents the ability of the optical system to deflect the light. Generally speaking, the light intensity is expressed as the reciprocal of the focal length of the image. Prism refers to the deviation of light produced by passing through a special point on the lens. In Europe EN1836:2005 sunglasses are divided into 2 grades, and different grades have different requirements for light intensity and prism degree.
A lens with or without binocular integral lens grade 1: horizontal tolerance 0.25cm/m (basement) ~0.75cm/m (basal outward) vertical tolerance 0.25cm/m.
4. material and surface quality
5. Various countries have certain requirements on the The surface quality of sunglasses, just differentiated in description, to sum up various requirements, it can be simply stated as follows: to test under bright and dark environment without the aid of optical amplification device, to see whether there are bubbles lens scratches, impurities, mildew, scratches, stains, blisters and cracks or not.
To meet the requirements of the national standard GB10810-1996 “5.1.4”, namely, there should be no inner defects effecting vision such as Huo Guang, and spiral within the field centered by lens datum point and within the diameter of 30nm, as well as no scratches, wear on the surface, keep clean and clear perspective.
6. Flame retardancy
In the European standard EN1836, the flame retardant test method of Australian standard AS/NZS1067 and China’s standard QB2457are basically the same and shown as follows:
Put the steel rods heated to (650 + 20) C above the sample for (5 + 0.5) s, and see whether the samples continued to burn. In ANSIZ80.3, to place the sample in （200±5）℃ for （15±1）min to observe whether the sample would burn. The two methods seem to be very different, but they are essentially discussing the same thing, that is, whether the high quality fake Oakleys will burn at high temperatures.