Why does the color of the high-pressure sodium lamp change during startup?
May 07, 2024
The main reason for the color change of high-pressure sodium lamps during startup is closely related to their working principle and the gas discharge process inside the lamp. Firstly, let's understand the basic working principle of high-pressure sodium lamps.
High pressure sodium lamp is a gas discharge lamp that uses sodium vapor as the working substance, while also filled with mercury vapor and rare gases to help activate and control color. During the startup process, the high-pressure sodium lamp underwent a series of physical changes. At first, when the power is turned on, the current passes through the heating resistance wire and the bimetallic switch, causing the temperature of both to rise. Due to different coefficients of thermal expansion, the contacts separate and generate high pressure, thereby illuminating the sodium lamp. After the lamp starts working, the thermal radiation of the arc maintains the temperature inside the shell and keeps the contacts separated.
Then, the two poles inside the triggered discharge tube begin to discharge through xenon and mercury gas, emitting a very dark white glow. As the pressure of mercury vapor increases, the color of the light gradually turns blue. Subsequently, sodium began to emit a single yellow light, and when the sodium vapor pressure was sufficient, the light eventually turned golden white.
This process explains why the color of high-pressure sodium lamps changes during startup. The color changes from the initial white glow, to blue, and finally to yellow are all caused by gas discharge and pressure changes inside the lamp.
We are a professional manufacturer and supplier of HPS street lights in China, specializing in providing high-quality, low-priced customized products. Our high-pressure sodium lamp products strictly follow this working principle to ensure that the lamp can smoothly undergo color changes during startup and ultimately emit high-quality yellow light stably. This yellow light has the advantages of strong penetration and high energy efficiency, and is therefore widely used in outdoor lighting places such as roads, airports, docks, and stations.
At the same time, we continuously optimize product design and improve color rendering index to meet the lighting needs of different customers. At the same time, our company also has a variety of high-quality outdoor lighting products, including LED street lights, lamp posts, and courtyard lights, which can meet the needs and preferences of different customers. If you have any needs in this regard, you can contact us directly.
