The utilization rate of school blackboards is very high, so it is necessary to meet the needs of blackboard lighting from the perspective of teachers and students. Blackboard lights can neither directly glare at teachers nor reflect glare at students, otherwise it will indirectly affect students' learning efficiency and vision.
After installing lamps in many classrooms, most engineers and school supervisors judge the brightness of lamps intuitively. Basically, they simply look around and then go to the next classroom for acceptance. They often don't use optical instruments to detect whether the light sources of these lamps are glare.
According to the national standard, the classroom blackboard should be provided with local lighting, the average illumination should not be less than 500lx, and the uniformity of illumination should not be less than 0.8.