Common Terms
for Fluorescent Lamps
 | Common Fluorescent
Lamp Configuration: Fluorescent lamps consist of a tube containing mercury vapor at low pressure and a small amount of inert gas, sealed with hot cathodes in each end. When energy is applied to these hot cathodes an electron flow is created that disturbs the electrons in the mercury, causing them to shift and give off radiation. Characteristics of fluorescent lamps are long life (12,000 to 22,000 hours), high efficacy (75 to 90 LPW), and excellent color rendering, especially with the Voltarc technology advanced phosphors. Fluorescent lamps are, however, temperature sensitive and their rated lamp life is dependent upon the number of hours per start. |
| Fluorescent Lamps are
Classified as: Preheat, Instant start and Rapid start. Preheat lamps: require a separate starter and few seconds of cathode filament heating time. Instant start: eliminated the need for starters. The lamp lights as soon as the circuit is closed. Rapid start: use smaller and more efficient ballast with filament heat present during operation. |
| Correlated Color
Temperature (CCT): The Correlated color temperature of a lamp is described in terms of its lighted appearance to the naked eye i.e.: whether it appears "warm" or "cool." The CCT is referenced to the Kelvin scale, ranging from 1500 K (red-orange color) to 9000 K (blue color) Most Light sources are between these two. CCT 4100 K and over appear "cool" and those of lower than CCT 3100 K appear "warm." |
| Color Rendering Index
(CRI): Color rendition is the attempt to describes the effect a light source has on the appearance of a colored object. Higher CRI equals less color distortion by the lamp. Maximum CRI is 100. CRI of 100 indicates that there is no color shift as compared to a reference source. Low CRI values denote a pronounced shift in color distortion. CRI values should only be compared between lamps of similar color temperature. |
