Image Credit: Newark / element14 | Allied Electronics, Inc. | Digi-Key Corporation
Fluorescent lamps are high-efficiency lamps that use electrical discharge through low-pressure mercury vapor to produce ultraviolet (UV) energy, which is then transformed into visible light. The UV excites phosphor materials applied as a thin layer on the inside of a glass tube, which makes up the structure of the lamp. The phosphors transform the UV to visible light. With fluorescent lamps, the wavelength of the emitted light is a function of the amount of energy that is released. As a rule, fluorescent lamps convert electricity to light with greater energy than incandescent lamps. They also work at cooler temperatures. Unlike incandescent lamps, fluorescent lamps cannot be connected directly to electric lines. Instead, fluorescent lamps require ballasts to stabilize the flow of current. Fluorescent ballast provides the starting voltage and limits the amount of current that can pass through the fluorescent lamp.
How a fluorescent light works - schematic animation Video Credit: EdisonTechCenter
Performance specifications for fluorescent lamps include rated average life, lamp power, initial lumens, mean lumens, color rendering index and color temperature.
- Rated average life is the lamp-burning hours to median life expectancy.
- Lamp power is the wattage of the lamp. Initial lumens is the initial light output.
- Mean lumens is the average lamp output over a designated amount of time, usually 40 to 50 % of rated lamp life. A lumen is the standard international (SI) unit of luminous flux or quantity of light.
- Color rendering index is an indication of a lamp's ability to render object colors in a normal, natural way. A higher number indicates better color appearance. Numbers range from 0 to 100.
- Color temperature is a measure of the visual "warmth" or "coolness" of the light from the lamp. The higher the value, the whiter or "cooler" the light appears.
Fluorescent lamps uses many different types of lamp bases: single-pin T-6, single-pin T-8, single- pin T-12, bi-pin T-5, bi-pin T-8, bi-pin T-10, bi-pin T-12, and 4-pin (circline). Recessed double-contact T-8 and recessed double-contact T-12 lamp bases are also available.
- Single-pin T-6 uses a small, single-pin connection.
- Single-pin T-8 uses a medium-sized, single-pin connection.
- Single-pin T12 uses a large, single-pin connection.
- Bi-pin T5 uses a miniature-sized, two-pin connection.
- Bi-pin T8 uses a small, two-pin connection.
- Bi-pin T-10 uses a medium-sized, two-pin connection.
- Bi-pin T-12 uses a large, two pin connection.
- Circline is a four-pin connection.
- Recessed double-contact T8 uses a small, recessed, two-pin connection.
- Recessed double-contact T-12 uses a large, two-pin connection.
ANSI C78.375 - Fluorescent lamps - guide for electrical measurements.
ANSI C82.13 - Definitions - for fluorescent lamps and ballasts for lamp ballasts.
IEC 61195 - Double-capped fluorescent lamps - safety specifications.IEC 61199 - Single-capped fluorescent lamps - safety specifications. Read user Insights about Fluorescent Lamps
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Halogen lamps are high pressure incandescent lamps containing halogen gases such as iodine or bromine, which allow the filaments to be operated at higher temperatures and higher efficacies.
Heat lamps are also known as infrared emitters, infrared bulbs, infrared tubes, or infrared lamps. Heat lamps differ from illuminating lamps in their low filament temperature, resulting in much less light and more infrared radiation.
High Intensity Discharge Lamps
High intensity discharge lamps (HID) contain compact arc tubes, which enclose various gases and metal salts, operating at relatively high pressures and temperatures. HID lamps are often used as UV light sources.
Incandescent lamps generate light by passing an electric current through a thin filament wire (usually of tungsten) until the wire is extremely hot.
Lamps are light sources that emit incoherent light for illumination. There are many different types of products. Examples include fluorescent lamps, halogen lamps, heat lamps, incandescent lamps, LED lamps, projection lamps, spectral lamps, and stage lamps. Specialized and proprietary lamps are also available.
Projection lamps use a built-in reflector to concentrate light in a particular direction. They are used in applications such as slide projection, microfilm, overhead projection, movies, medical / scientific instruments, airport runways, and others.
Stage lamps are used for stage, studio, or television lighting. They are often made of quartz instead of glass to provide higher pressure ratings, higher melting temperatures, and more energy-efficient designs.