Although incandescent lamps are still used more, they are gradually being replaced by other light sources due to their low luminous efficiency and short life. Among them, single-plug non-starter fluorescent lamps, self-ballasted high-pressure mercury lamps and high- pressure sodium lamps are more commonly used.

The single-plug starter-less fluorescent lamp is a cold cathode gas discharge lamp. The light-emitting principle is to use the discharge between the electrodes to generate ultraviolet radiation from mercury atoms, thereby exciting the fluorescent material on the inner wall of the tube to emit light. This kind of fluorescent lamp has a high luminous efficiency (about 3 times that of an incandescent lamp), a long service life, and does not require a starter when starting (usually there is a conductive layer on the lamp tube wall , called a glow layer, which is the glow of a fluorescent lamp Rely on it to complete; when the lamp tube is broken, the luminous layer is also destroyed, and the lamp is extinguished), the cathode temperature is low (about 200 ℃ ), it is a safe and practical light source, very suitable for making increased safety lighting lamps.

The self-ballasted high-pressure mercury lamp is a hybrid light source lamp that uses high-pressure mercury vapor discharge and three types of incandescent and fluorescent substances to emit light. It has the advantages of high brightness, simple structure and fast starting speed. The shortcomings of the previous high-pressure mercury lamps that require an external ballast are changed, and the tungsten wire is used to limit the current and also improve the light color. The disadvantage is that the life span is shorter than that of ordinary fluorescent high -pressure mercury lamps. The high-pressure sodium lamp is a high-pressure sodium vapor discharge lamp, which has the advantages of high luminous efficiency, low power consumption, strong fog penetration ability and long life.

The production facilities of the author\'s unit now mainly use single-plug non-starter fluorescent lamps and self-ballasted high-pressure mercury lamps. The original fixed explosion-proof incandescent lamp, under the condition of meeting the minimum distance between the bulb and the transparent cover specified in the regulations, has been approved by the relevant unit, and replaced the incandescent bulb with the original lamp with a self-ballasted high-pressure mercury bulb. Although the high-pressure sodium lamp has a certain energy-saving effect, because of its poor color rendering, we generally do not use it in the production device, and only use it for road lighting. Sometimes in order to improve the direct white light color emitted by the high-pressure mercury lamp, some high-pressure sodium lamps can als