Just like any light bulb you would use for another
purpose, projector bulbs have an expected operating time, called lamp
life. This value is expressed in number of hours - typically 1000 to
2000 hours. Newer models are claiming 4000 hours of lamp life and more.
The lamp's success rate is based on a bell curve, so that a majority of
(but not all) lamps will meet the lamp life hours specified. Some lamps
will fail sooner and this is part of the acceptable operating range of
the rating.
For projectors that are used under normal operating
conditions (no more than three to five hours per day in a clean,
relatively dust-free environment) the lamp will have the greatest
likelihood of lasting through its entire rated lamp life. Projectors
that are used more often or are exposed to environmental contaminants
are more likely to show a decrease in lamp life. Projectors that are
operated 24 hours a day, 7 days a week are at the highest likelihood of
lamp failure before the end of the rated hours.


