What's a t-5 balast
- Thread starter alison
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scubasteve
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Here's an excperpt from an acrticle by Craig DiLouie
"The T5 lamp was first unveiled at Hannover Fair in 1995 and introduced to North America in 1996. The T5HO, which produces twice the light output of a T5 lamp while being the same length, was introduced to Europe in 1997 and North America in 1998. Since then, T5 lamps have carved out a share of the lamp market due to a unique combination of advantages and disadvantages.
T5 and T5HO lamps are immediately distinguishable for their slim profile. The T means the lamp is tubular in shape; the number, divided by eight, is the lamp’s diameter in inches. So the T12 lamp is 1-1/2 inches in diameter, the T8 lamp is one inch in diameter, and the T5 is 5/8 inches in diameter.
The lighting industry, in particular lighting designers and high-end fixture manufacturers, were quick to grasp the potential of T5 lamps to be used in slimmer and more compact fixtures and follow the popular trend of “smaller is better.” Since the lamp is 40 percent smaller than T8 lamps, the fixture should be 40 percent smaller, went the reasoning. In addition, the slim diameter enables better photo-optic control of the light emitted in the fixture, increasing fixture efficiency and providing uniform light distribution.
Light output and efficacy. A 28W T5 lamp produces about the same light output as a 32W T8 lamp during system operation. The lamp, however, is more efficacious (initial lamp efficacy of 104 lumens per watt for a 28W T5 vs. 94 LPW for a 32W T8). T5 lamp-ballast systems also operate at a higher efficacy than T8 lamp-ballast systems (96 LPW at 8,000 hours of operation for a T5 system with a 28W T5 lamp vs. 89 LPW at 8,000 for a T8 system with a 32W T8 lamp). T5HO initial lamp and maintained system efficacy, meanwhile, is somewhat less than that for the T8. In addition, T5 lamps contain a very small amount of mercury (3mg), have good color rendering (82 CRI), and offer high lumen maintenance (about 95%).
With a thinner tube, more light is output from a smaller surface area, making the lamp brighter—brighter than a T8 lamp but less bright than compact fluorescents. This effect, of course, becomes pronounced when using T5HO lamps, which produce nearly twice the light output of T5 lamps (with the same surface area) and close to twice that of T8 and T12 lamps, and can result in discomfort glare.
“T5 lamps can be used anywhere T8 and T12 lamps are currently used,” says Jeff Waymouth, LC, Senior Applications Engineer - Fluorescent Lamps, for OSRAM SYLVANIA, Inc., a lamp and ballast manufacturer. “Since the lamps are so much brighter, T5HO lamps should be used in applications where they are not directly visible.”
"The T5 lamp was first unveiled at Hannover Fair in 1995 and introduced to North America in 1996. The T5HO, which produces twice the light output of a T5 lamp while being the same length, was introduced to Europe in 1997 and North America in 1998. Since then, T5 lamps have carved out a share of the lamp market due to a unique combination of advantages and disadvantages.
T5 and T5HO lamps are immediately distinguishable for their slim profile. The T means the lamp is tubular in shape; the number, divided by eight, is the lamp’s diameter in inches. So the T12 lamp is 1-1/2 inches in diameter, the T8 lamp is one inch in diameter, and the T5 is 5/8 inches in diameter.
The lighting industry, in particular lighting designers and high-end fixture manufacturers, were quick to grasp the potential of T5 lamps to be used in slimmer and more compact fixtures and follow the popular trend of “smaller is better.” Since the lamp is 40 percent smaller than T8 lamps, the fixture should be 40 percent smaller, went the reasoning. In addition, the slim diameter enables better photo-optic control of the light emitted in the fixture, increasing fixture efficiency and providing uniform light distribution.
Light output and efficacy. A 28W T5 lamp produces about the same light output as a 32W T8 lamp during system operation. The lamp, however, is more efficacious (initial lamp efficacy of 104 lumens per watt for a 28W T5 vs. 94 LPW for a 32W T8). T5 lamp-ballast systems also operate at a higher efficacy than T8 lamp-ballast systems (96 LPW at 8,000 hours of operation for a T5 system with a 28W T5 lamp vs. 89 LPW at 8,000 for a T8 system with a 32W T8 lamp). T5HO initial lamp and maintained system efficacy, meanwhile, is somewhat less than that for the T8. In addition, T5 lamps contain a very small amount of mercury (3mg), have good color rendering (82 CRI), and offer high lumen maintenance (about 95%).
With a thinner tube, more light is output from a smaller surface area, making the lamp brighter—brighter than a T8 lamp but less bright than compact fluorescents. This effect, of course, becomes pronounced when using T5HO lamps, which produce nearly twice the light output of T5 lamps (with the same surface area) and close to twice that of T8 and T12 lamps, and can result in discomfort glare.
“T5 lamps can be used anywhere T8 and T12 lamps are currently used,” says Jeff Waymouth, LC, Senior Applications Engineer - Fluorescent Lamps, for OSRAM SYLVANIA, Inc., a lamp and ballast manufacturer. “Since the lamps are so much brighter, T5HO lamps should be used in applications where they are not directly visible.”
