Technical indicators Sunglasses(2)

The average transmittance

(UV)

The average transmittance in value is the average transmission Cheap Ray Ban Sunglasses lens in the UV spectral range of ultraviolet radiation than, standard:

A) in the 315nm to 380nm UVA band, the average transmission ratio τ SUVA τ V ≤;

B) in the 290nm to 315nm UVB band, the average transmission ratio τ SUVB τ V ≤ 0.5.

In addition, in the UVB band, light-colored Sunglasses average transmission ratio should be below 30%, sunshade mirror average transmission ratio should be below 5%.

When the sunglasses to meet this requirement, reach the basic requirements for protection, which also blocked the corresponding amount of light in the UV blocking at the same time, wearing the sunglasses at least will not increase the amount of light received (wear sunglasses, will reduce the into the eye pupil flux, resulting in increased wear, in the same exteal conditions if the UV, sunglasses, can stop the corresponding amount of human will receive more light than wearing sunglasses when). In 2006 November, the formal implementation of the GB10810.3 "glasses and related products - Part third: transmission than the standard and measurement methods", defined as sunglasses lenses, UV transmittance shall not exceed a maximum of 5%.

With anti-ultraviolet function of sunglasses, generally express the following:

A) Marked "UV400": the representation of Ray Ban Sunglasses lens on the UV cutoff wavelength is 400nm, namely the wavelength (lambda) in the spectral transmission below 400nm than the largest value max (λ) is less than 2%;

B) Marked "UV", "ultraviolet": this says the lens to UV cut-off wavelength is 380nm, namely the wavelength (lambda) in the spectral transmission below 380nm than the largest value max (λ) is less than 2%;

C) Labeled "100%UV absorption": this says lens has 100% absorption function of ultraviolet, namely the average transmission in the UV range is less than 0.5%.

To achieve the above requirements of sunglasses is the real sense has the protective function of UV sunglasses.

Ultraviolet resistant performance is an important indicator of whether a pair of sunglasses, sunglasses with UV protection function, we can not distinguish with the naked eye. China's current standard on the UV protection only basic requirements, namely the wearer harmless. Protection functions mainly by the production enterprise to express acceptance, but not all Sunglasses products have anti-ultraviolet function, as consumers to identify whether a product with anti-ultraviolet function, only to the factory products Express acceptance as the only reference.

Color limit

Through the lens of yellow and green traffic signal and through the lens of average daylight simulation, prescribed in the standards: color coordinate corresponding shall be located in a chromatin diagram (QB2457-1999 1) in the corresponding region. If the measured color coordinates value exceeds the limit prescribed by the color region, will cause the confusion of various traffic signal, is one of the hidden danger of traffic accidents.

Traffic signal transmission ratio

Through the lens of red, yellow, green traffic signal, the standards stipulated in the relevant for the transmission of traffic signal ratio: the red signal should be greater than or equal to 8%; the yellow and green signal should be larger than or equal to 6%; if all kinds of traffic signal transmission ratio is too low, it reduces the signal recognition ability, also is one of the potential traffic the accident.

Mark

According to the requirements of the QB2457-1999 on the logo, standard code for each pair of glasses should be marked executed (QB2457), categories (sunshade mirror or light-colored sunglasses) and the manufacturer name and trademark. Classes marked, for consumers to correct choose according to use and place in the selection of sunglasses.

Impact resistance

To express with protection function or with ANSI (American national standard) Cheap Ray Bans lens, the height of free falling ball impact must be able to withstand 16g from 1.27m without fragmentation. The index is the minimum requirement for protective glasses. If express lens has a protection function, but also pass the standard, it is likely to mislead consumers in an unsafe place wears a pair of glasses that are safe, if have an accident occurs, will directly harm the consumer's eye.