GE Light Bulb Output Characteristics

Lumens

• To assess the brightness of a light bulb, check its ratings for a value measured in lumens. Just as the measurement of horsepower references a bygone era in transportation, a lumen relates to candle power, specifically the light emitted by one standard candle. Depending on the type of bulb, today's bulb ratings can include initial and mean lumen ratings to reference the amount of light a new bulb produces and its reduced output as it ages. Measurement calculation formulas vary depending on the type of bulb. For example, a T5 fluorescent lamp's initial rating measurement represents its output after 100 operating hours, and its mean rating comes at 40 percent of the rated lifespan of the lamp. Lumen ratings may not reflect actual light output in a specific installation, with variances caused by the amount of light that a location reflects or absorbs, and the differences in brightness that can occur depending on how you orient some types of bulbs -- base up or down -- when you install them.

Wattage

• GE's wattage ratings represent the amount of electric current a bulb draws in operation and can relate directly to the amount of light it emits. However, as general-use incandescent bulbs phase out in the U.S. under Federal law requiring more efficient light sources, wattage ratings no longer provide the best comparison of bulb types. New lamp technologies -- including expanded use of fluorescents, new types of halogen bulbs and new LED lighting -- make wattage an outdated measure of bulb performance. These new technologies can produce higher lumen ratings at lower wattages. For example, GE's 60-watt replacement LED bulb uses only 13 watts to produce 800 lumens.

Rated Life

• Along with specifications that describe a bulb's output characteristics, GE also provides an estimate of its working lifespan. The rated life of an 800-lumen bulb designed for general use can range from 2,500 hours for halogen, 12,000 for compact fluorescent or 25,000 for LED. Because bulb operating cost factors into purchase price, electrical use and expected use, the higher rated life you can achieve from new bulb technologies can help you stretch your budget by reducing the number of bulbs you need to buy.

Other Considerations

• Bulbs come in a multitude of shapes, base types, colors and color temperatures, single- or multiple-output settings and indicated usages. Bulb shapes and base types represent intended implementations, ranging from standard bulbs for table lamps, ceiling fixtures to flame-shaped bulbs for decorative lamps and plug-in versus screw-in fluorescents. Some bulbs include a colored coating designed to make them emit equivalently colored light for special decorative uses. Among standard-coating bulbs, color temperature ratings enable you to compare the appearance of the light emitted by a bulb to the illumination of other bulb types or natural light.