Sunglasses measurements: average ultraviolet transmittance and traffic signal transmission ratio
Detection of the main indicators are: the optical performance of lens, frame properties, assembly and cosmetic requirement, transmission characteristics ( Including light transmittance, the average transmittance of ultraviolet spectrum area, the traffic signal identification of projection than features such as color limit) Mechanical impact resistance, etc. Key indicators have coke, prism of the deviation degree, average optical transmittance, uv transmittance ( Ultraviolet spectrum area) And traffic signal transmission ratio. This paper mainly introduces the average transmittance of ultraviolet ( Ultraviolet spectrum area) And traffic signal transmission ratio. The average, uv transmittance ( Ultraviolet spectrum area) Average ultraviolet transmittance reflects the sunglasses ultraviolet light through the situation, through the smaller, the stronger the ultraviolet prevention ability. In 315 nm to 380 nm UVA wavelengths, the average transmittance rSUVA rv or less; In the 290 nm to 315 nm UVB wavelengths, the average transmittance rSUVB 0 or less. 5 rV。 When sunglasses meet the indicators, to reach the basic requirement of the protection, namely in blocking light did not increase at the same time to accept the amount of ultraviolet light. Due to wear sunglasses, can reduce the luminous flux into the human eye, which increases the wearer pupil, so under the same external conditions, if sunglasses can't stop the corresponding amount of ultraviolet light, the eye will accept more than when not wearing sunglasses ultraviolet light, namely to wear dark sunglasses uv than not wearing sunglasses the damage to the eyes. Second, traffic signal transmission than the index of traffic signal transmission ratio of main control, guarantee objects of different colors in different color sunglasses, can keep the original color chromaticity object. The technical requirements of sunglasses is also very important, imagine if a pair of sunglasses for traffic signal transmission ratio falls below, can reduce the resolution of the wearer to color and the interference color vision, color confusion, for the pilot, consequence is unimaginable. QB2457 - 1999 'sunglasses' traffic signal transmission ratio (standard specified by rsig) Requirements of the standard value. For light color sunglasses, red signal: 8% or more; Yellow signal: 6% or more; Green signal: 6% or more; Sunshade sunglasses traffic signal transmission ratio requirements as above; For special use sunglasses, such as skiing, mountain climbing, beach, etc. , the traffic signal transmission no requirements than the index.