- Fluorescent Lamp Definition: A fluorescent lamp is defined as a light source that uses low-pressure mercury vapor and phosphor coating to produce visible light.
- Components: The construction of a fluorescent lamp includes a lime glass tube, mercury, argon gas, a phosphor coating, electrode coils, and aluminum caps.
- Electrode Function: The electrodes, acting as both anode and cathode, are coated with oxides to emit free electrons and are protected to reduce wattage loss.
- Gas and Pressure: The lamp contains low-pressure mercury vapor and argon gas, with pressure inside the lamp at around 0.3% of environmental pressure.
- Shapes and Sizes: Fluorescent lamps are available in straight, U-shaped, and spiral forms to suit various lighting applications.
A fluorescent tube light consists of
- a lime glass tube
- drop of mercury
- argon gas
- phosphor coating
- electrode coils
- mounting assemblies
- aluminum cap
Total set up of a lamp requires two bases and electromagnetic ballast or choke coil with a starter.
- The electrode mount assemblies are at both the ends of lamp tube.
- This electrode mounting assembly is almost similar to the stem press unit in the incandescent lamps.
- The electrode is similar to the incandescent lamp filament.
- The filaments of electrodes play both roles as anode and cathode.
- Small plates are attached to the filament to protect the electron bombardment and reduce the wattage loss at both ends.
- The filament is coated in a mixture of barium, strontium, and calcium carbonate. During manufacturing, it is baked to form oxides, allowing it to emit a large number of free electrons easily.
- Liquid mercury is provided inside the lamp bulb.
- Phosphor coating is used on inner wall of the bulb tube.
- At a certain pressure argon gas is filled up inside the tube.
- Two pins at each end are taken out of the lamp body through the cap.
The figure of an electrode is shown below.
A fluorescent lamp tube contains low-pressure mercury vapor and argon gas, with pressure inside the lamp at about 0.3% of environmental pressure. The inside surface of the lamp is coated with fluorescent material made of various metallic and rare earth phosphor salts. The anodes, usually made of coiled tungsten, are coated with a mix of barium, strontium, and calcium oxides for low emission temperature. Fluorescent lamp are typically straight and long, around 100 millimeters (3.9 in). Some lamps are twisted into circles for compact spaces, while U-shaped and spiral lamps are used for different lighting needs.
To construct a fluorescent tube light, you need a lime glass tube, a drop of mercury, argon gas, a phosphor coating, and electrode mount assemblies. The complete setup includes two bases and a choke coil with a starter. The electrode mount assembly is similar to the stem press unit in incandescent lamps. The filaments serve as both anode and cathode, with small plates attached to reduce electron bombardment and wattage loss.
The electrode is similar to the incandescent lamp filament. But an exception is that this filament is dipped in a mixture of barium, strontium, and calcium carbonate. It is baked during manufacturing to become oxides and thus it becomes capable of providing the abundance of free electrons easily.
