1 - The projector image seems dimmer than usual - what does this mean?

It may be time to replace your projector lamp. With metal halide (high pressure mercury) lamps, you'll notice a dimming of the image brightness as the lamp loses power. Some projectors allow you to check the number of hours your lamp has been used through the built-in menu system. Check your user guide for information about this feature.

2 - How many hours will my projector lamp work?

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.

3 - What can I do to help my projector lamp last longer?

Do not allow the projector to become overheated. The number one cause of lamp failure is excessive heat. Follow the instructions in the user manual for powering down the projector to ensure that the projector has had an adequate cool-down period.

Operate your projector in a clean, relatively dust-free environment. Clean air filters regularly.

Utilise the "economy mode" if it is available with your projector model.

4 - What is the difference between a halogen and metal halide lamp?

Halogen bulbs last approximately 70 hours (per bulb). Metal halide lamps last approximately 1000 to 2000 hours.

Halogen lamps are less expensive than metal halide lamps . The type of lamp your projector uses will be determined by the manufacturer.

Halogen lamps give off a yellowish image and metal halide lamps have a whiter image.

Halogen lamps burn at a steady rate and have a consistent brightness throughout lamp life. The brightness of metal halide lamps decreases during lamp life.

5 - What about UHP?

UHP (Ultra High Performance) is a proprietary design of metal halide lamp manufactured by Philips that requires lower wattage for equivalent brightness. The benefits of this technology are a smaller and lighter projector, because the power supply is smaller and lighter; a cooler running, quieter, and less expensive-to-operate projector because of the lower wattage; and a longer lamp life, because the stresses on the lamp (wattage, temperature change) are reduced. UHP lamps last approximately 4000 hours whereas metal halide lamps last approximately 1000 to 2000 hours.

Tips for longer projector lamp life

Lamp life for a projector will vary based on many factors including application, installation, intake of cool air and exhaust of hot air, usage and proper maintenance. Heat buildup can reduce lamp life and even damage your projector.

Here are some tips to help your projector lamps last longer:

1. Once you turn on your projector, wait at least five minutes before turning it off to allow the fan to properly cool the unit. After the fan has cooled your projector, you may unplug it and store it as desired.

2. Do not obstruct the air intake or exhaust vent. Paper should not be placed on top of a projector or where vents are located.

3. Keep the exhaust vent at least 2 feet from any object.

4. If the projector is built into a compartment, wall, ceiling or shelf mount, the minimum distance requirement (usually at least 2 feet) stated in your owner's manual must be maintained.

5. Clean the projector's air intake filter every three to six months — or more frequently — based on your operating environment.

6. Do not move your projector until the lamp has cooled (about five minutes).

Schools and IT departments may wish to print these tips and keep them with projectors for end users to reference.

SOURCE: AVI Presentation Press e-newsletter July 2003 issue · POSTED: 07/10/03