In the Swedish capital of Stockholm in winter, whenever the sun sets at 15:00 pm, the whole city sinks into the dark and gloomy. More than half of people in this environment will become depressed and lethargic, and looks like...
Near-infrared spectroscopy history and principle Infrared light is a portion between the visible and microwave regions of the electromagnetic spectrum ranging from 700 nm to 1 mm. Infrared light was discovered by a German-British astronomer named William Herschel in 1800...
1. CIE 1931 The CIE 1931 were created by the International Commission on Illumination (CIE) in 1931. And this is the first time human created an explanation between distributions of wavelengths in the visible spectrum, and colors can be perceived...
We often see luminous flux or illumination data on the packaging of light bulbs or other lamps. Maybe you know these two parameters are used to describe the brightness of light. But what are the specific definitions of luminous flux...
Scientific research indicates that light is one of the main driving forces of the circadian system, whether it is natural sunlight or artificial light sources, they are all can trigger a series of physiological rhythm reactions. As we all know,...
1. Background Generally, in order to meet the new demand of solid-state lighting (SSL) market and communicate with consumers about the color quality of lighting products, NIST (National Institute of Standards and Technology) has developed the light color quality meter,...
The feeling of the sunlight, as we know, is different from morning till night in nature. According to the position where the sun moves in the sky, the color of the sun will turn into red, orange, yellow, and white....
PART V: “LIFETIME” Lifetime is a critical index for evaluating lighting fixtures. Conventional lighting fixtures are relatively inexpensive, of which the most widely adopted type is the fluorescent light, with only 3000 hours’ longevity. Compared to that, LED lights are...
PART IV: “COLD LIGHT SOURCE” Before LED lighting technology came to maturity, greenhouses were the major form of artificial plant factories. In greenhouses, temperature condition can be better controlled than plants grown outside, and sunlight is obtained during the day...
