The purpose of tungsten filament is to connect in series with quartz lamp tubes in mercury lamps. The mercury lamp uses mercury vapor generated when mercury is discharged to obtain visible light as an electric light source. Mercury lamps can be divided into three types: low-pressure mercury lamps, high-pressure mercury lamps and ultra-high-pressure mercury lamps. When the low-pressure mercury lamp is ignited, the mercury vapor pressure is less than one atmosphere. At this time, the mercury atoms mainly radiate ultraviolet light with a wavelength of 253.7nm.
When tungsten wire is used in a high-pressure mercury lamp, the inner wall of the glass shell is not coated with phosphor, but a tungsten wire is connected in series between the shell and the quartz lamp. of red light to improve the light color. This type of high-voltage incandescent mercury lamp is easy to use and can be directly connected to a 220-volt AC power supply. Its luminous efficiency is lower than that of a high-voltage fluorescent mercury lamp, but higher than that of an incandescent lamp. The central part of the lamp is the discharge tube, which is made of quartz glass. The tube is filled with a certain amount of mercury and argon. Tungsten is used as the main electrode and filled with alkaline earth metal oxide electron-emitting materials. The electrode and quartz glass are hermetically sealed with molybdenum foil. Generally, an auxiliary electrode is used for starting, which is connected to a non-adjacent electrode through a 40-60κΩ resistor. In addition to its protective function, the outer casing also prevents the environment from affecting the lamp.
Precautions
Preservation method: Store in a cool and sealed place, away from direct sunlight.
1. Transformers and capacitors of corresponding specifications must be equipped when used;
2. Before use, the surface of the lamp must be wiped clean with absolute ethanol, and it is strictly forbidden to touch it directly with your hands;
3. The lamp produces strong long-wave violet radiation (the main wavelength is 365 nanometers) by high-pressure mercury vapor discharge;
4. Strong ultraviolet rays can burn eyes and skin, so direct light exposure should be avoided during use;
5. The lamp is accidentally damaged, resulting in the emission of mercury vapor. On-site personnel must leave immediately and allow the site to continue to be ventilated for 20-30 minutes to prevent mercury vapor from being inhaled into the body and causing poisoning. When it is safe, the site should be cleaned up in time, and the recycled mercury raw materials can be Reserved for experimental purposes.
