In recent years, with the frequent occurrence of safety accidents in some special dangerous places such as coal mines and chemical enterprises, the state has gradually increased the importance of safety production. Special electrical products such as explosion-proof electrical appliances and explosion-proof lamps are very important in the process of safe production.
Explosion-proof lamps are a kind of electrical products used in explosive environments. According to their different explosion-proof types, they are mainly divided into: flameproof type "d", "n" type, increased safety type "e", dust explosion-proof type "DIP" and composite explosion-proof type composed of two or more explosion-proof types, etc. Its design, inspection, production, installation, use and maintenance must comply with the relevant regulations of explosion-proof standards and related standards.
As explosion-proof electrical products, explosion-proof lamps have certain special characteristics. Because of their luminous and heat-generating characteristics, it is not easy to meet the requirements of explosion-proof electrical energy limit and temperature limit. Therefore, special attention should be paid to the control of their energy generation in their design and manufacture.
Everyone knows that the "maximum surface temperature" is a crucial factor in an explosive atmosphere, which refers to the surface or any part of the electrical equipment that may reach and possibly ignite the surrounding explosive when operating under the most unfavorable conditions allowed. The maximum temperature of the gas environment. As an electrical product that can quickly generate high temperature and high heat, the "maximum surface temperature" is even more critical for the lamp itself. Then, when the inspection agency tests explosion-proof lamps, the temperature test is the most important and the most difficult to operate.
1. According to the type of light source: explosion-proof incandescent lamps, explosion-proof fluorescent lamps, explosion-proof high-pressure mercury lamps, explosion-proof sodium lamps, explosion-proof metal halide lamps, LED explosion-proof lamps, etc.;
2. According to the installation type, it is divided into: ceiling type explosion-proof lamp, wall-absorbing explosion-proof lamp, hanging type explosion-proof lamp, embedded explosion-proof lamp;
3. According to its use, it can be divided into: explosion-proof lighting, explosion-proof flood light, explosion-proof signal light, explosion-proof emergency light, explosion-proof mobile light;
There are also some differences in the methods used in the test for different lamps.
Explosion-proof lamps should pay attention to the following points when conducting temperature tests:
1. Explosion-proof type of lamps;
2. The installation method and light source of the lamps;
3. Optical principle (light-emitting type);
4. Selection of temperature test points.
During the test, the test personnel should analyze the lamps with different light sources, different installation methods, and different optical principles, and then select a reasonable temperature test point, which is also the most important step in the temperature test.
(1) Explosion-proof type
Different explosion-proof type lamps have different test points for temperature test. For example, when measuring the maximum surface temperature of explosion-proof lamps, only the surface temperature of the test sample shell is used, but for increased safety and "n" type lamps, it is necessary to test the maximum temperature of the surface of the electrical components inside the lamp body such as the terminal and the surface of the light source.
(2) Installation method and light source
Due to the physical phenomenon that hot air will rise upwards, different installation methods will affect the selection of the maximum surface temperature of explosion-proof lamps. For the same lamp body, the calorific value of different light sources is also different. When measuring the temperature, the light source with the highest calorific value should be considered for assessment.
(3) Optical principle
Depending on the working principle and the light gathering point, the highest point of heat generation will vary.