Before explaining the problem, let's get familiar with it. What is the concept of 70% light transmittance? The light transmittance of the ordinary lighting glass we usually use is 80% and the light transmittance of the front windshield glass of the car without film is generally between 75% and 85%. Now we have an intuitive understanding of the light transmittance of 70%. The light transmittance of the front windshield must reach 70% or more.
GB9656-2016 automotive safety glass regulations on light transmittance of front windshield
The safety standard is that the visible light transmittance of the front windshield and glass outside the windshield for the driver's viewing area (referring to the part where the driver observes the rear view mirror when driving) should be 70% or more. Window glass must not be covered with a mirror reflective sunshade. In other words, the film of the front windshield must also reach a light transmittance of more than 70% in order to meet the national standard requirements. Otherwise, the car can’t pass the annual inspection of the vehicle management institute.
For safety reasons, the front windshield film must also ensure that the driver's vision is clear. Originally, the front windshield film was designed to prevent glass from hurting people in emergency situations (emergency situations such as car collisions). For safety, the film of the front windshield must be affixed according to national standards and the light transmittance must be greater than 70% to ensure driving safety.
Linshang is a professional manufacturer of light transmission meters. There are LS110 split-type light transmission meters and LS110A split type. Both of these instruments use split design.