Illumination is closely related to people's lives. Sufficient light can prevent people from accidents. On the contrary, too dim light can cause human fatigue far more than the eyes themselves.
Therefore, uncomfortable or poor lighting conditions are one of the main causes of accidents and fatigue. Existing statistics show that about 30% of all occupational labor accidents are directly or indirectly caused by insufficient light.
The lighting requirements for stadiums (halls) are very strict. Too strong or too dark lighting will affect the effect of the game.
So, what are the hygiene requirements for indoor contrast where people live? Illumination is a very important indicator in hygiene. Light refers to the electromagnetic radiation that can cause the human eye to feel bright, and the perception that can be produced when the light enters the eye is called vision. The light that people see refers to visible light, and its wavelength ranges from 380 to 760 nm (nanometers).
Lighting can be divided into two categories: natural lighting and artificial light. Natural lighting refers to the natural illuminance of indoor and regional areas, including direct sunlight scattered light and reflected light from surrounding objects, which are commonly expressed by daylighting coefficient and natural illuminance. The daylighting coefficient refers to the ratio of the effective area of the daylighting opening to the indoor floor area.
The daylighting coefficient of a general residence is between 1/5 and 1/15, and the living area ratio is between 1/8 and 1/10 (window area/indoor floor area). The natural illuminance coefficient is used to evaluate the illuminance level of natural light. It reflects the relationship between indoor and outdoor light exposure. Also reflects the local light climate (sum of natural light energy and solar illuminance indicators for climate).
In order to ensure that people live in suitable light, my country has formulated hygienic standards for indoor (including public places) illumination. For example, the illuminance hygiene standard of shopping malls (shops) in public places is ≥100Lx; the hygiene standard of the countertop illumination in libraries, museums, art galleries, and exhibition halls is ≥100Lx; the illumination hygiene standard of public bathrooms is ≥50Lx; bathroom (shower, pool, tub) ≥ 30Lx, sauna ≥ 30Lx.
Foreign standards for indoor illumination, such as Germany recommends several rated light intensities, 300Lx for office including paperwork, 750Lx for typing and drawing work; 1000Lx for visual work in factories and production lines; 1000Lx for hotels and public rooms 200Lx; reception points and cashier cabinets are 200Lx; shop windows are 1500~2000Lx; hospital wards are 150~200Lx, emergency treatment areas are 500Lx; schools and classrooms are 400~700Lx; canteens, indoor gyms are 300Lx, etc.
For the measurement method of illuminance, it is generally measured with an illuminometer. The illuminometer can measure the intensity of different wavelengths (such as the measurement of visible light band and ultraviolet band), and can provide people with accurate measurement results.
In a word, illuminance and human health, especially the health of eyes, have extremely important hygiene significance.
