Features and technical parameters of commonly used light sources

Features of low-pressure sodium lights: low-pressure sodium lights are different from other light sources. The emission wavelengths are 589.0nm and 589.6nm monochromatic light. The locations of the two yellow spectral lines are close to the green line with a wavelength of 555.0nm to which the human eye is most sensitive, which has high luminous efficiency, without producing color differences in the human eye; therefore, it has high view resolution and good contrast, suitable for places requiring high visibility and color rendering such as roads, viaducts, tunnels and intersections. Low-pressure sodium lights are also non-dazzling, and do not cause environmental gases erosion which leads to premature failure of optical systems. The luminous efficiency of low-pressure sodium light is up to 200lm / W, which is the light source with the highest efficiency; the life is up to 10,000 hours. Features of energy-saving lights: energy-saving light is also known as compact fluorescent light (or CFL light overseas), which was invented in 1978 by a foreign manufacturer. It has high luminous efficiency (5 times that of ordinary light bulbs), obvious energy-saving effect, long life (8 times of ordinary light bulbs), small size, easy to use and other merits. A 35 watts low pressure sodium light has a luminous flux of 5250 lumens (that of a 1 watt low pressure sodium is 150 lumens), equivalent to the brightness of a 350 watts incandescent light (the luminous flux of a 1 watt incandescent lamp is 15 lumens); the luminous flux of a 45 watts energy-saving lamp is 2250 lumens (the luminous flux of a 1 watt energy-saving light is 50 lumens), equivalent to the brightness of a 150 watts incandescent light (the luminous flux of a 1 watt incandescent light is 15 lumens). Taking into account the impact of color rendering, the brightness of a 35-watt low-pressure sodium light is equivalent to that of a about 150 watts incandescent light; the brightness of a 45-watt energy-saving lamp is equivalent to that of a 125-watt incandescent light.