The difference between low pressure sodium lamp and high pressure sodium lamp
1. Low pressure sodium lamp
Low-pressure sodium lamp is an electric light source that uses low-pressure sodium vapor discharge to emit light. Its glass shell is coated with an infrared reflective film. It is an electric light source with low light decay and high luminous efficiency. The low-pressure sodium lamp emits a monochromatic yellow light, which is used in places where there is no requirement for light color, but its "fog permeability" is very good, especially suitable for highways, traffic roads, municipal roads, public circles, and courtyard lighting , Can make people see objects with relatively small color difference clearly. Low-pressure sodium lamp is also a kind of high-efficiency lamp that replaces high-pressure mercury lamp to save electricity, and its application places are also expanding.
The low-pressure sodium lamp is a low-pressure sodium vapor discharge tube. The inner tube is blown with special anti-sodium glass. After being ignited, it can radiate 5890A and 5896A sodium spectrum. It can be used as a polarimeter, refractometer, polarimeter and other optical instruments. Monochromatic light source.
2. High pressure sodium lamp
The working vapor pressure of the high-pressure sodium lamp is greater than 0.01 MPa. The high-pressure sodium lamp is developed for the shortcomings of low-pressure sodium lamp such as strong monochromaticity, poor color rendering, and too long discharge tube. The high-pressure sodium lamp is divided into ordinary type (standard type), its luminous efficiency is 130lm/W, color rendering index Ra=25; improved type, its luminous efficiency is 75lm/W, color rendering index Ra=60; high color rendering type, its The luminous efficiency is 45-60lm/W, and the color rendering index Ra=80-85. What is produced is yellow light. The high pressure sodium lamp is composed of translucent polycrystalline alumina (PCA) ceramic arc tube, outer bulb, metal bracket, getter and lamp cap. The arc tube is the core element, filled with mercury, sodium and inert gas. When discharging, the internal sodium vapor pressure is 10-100kPa.
The high-pressure sodium lamp emits golden white light when in use. It has the advantages of high luminous efficiency, low power consumption, long life, strong fog penetration and no insect attraction. It is widely used in roads, highways, airports, docks, docks, stations, squares, street intersections, industrial and mining enterprises, parks, courtyards, and plant cultivation. High-color-rendering high-pressure sodium lamps are mainly used for lighting in stadiums, exhibition halls, casinos, department stores and hotels.
