When purchasing a surge suppressor:

■Make sure the surge suppressor meets the appropriate product safety certification for your location, such as Underwriters Laboratories (UL).

■Check the maximum amount of voltage the suppressor allows to pass through the line. The lower the voltage that the suppressor allows to pass through, the better the protection for your computer.

■Check the energy absorption (dissipation) rating. The higher the energy absorption rating, the better the protection for your computer.

■Check for line-conditioner capabilities. A line conditioner smooths out some of the normal line noise (small voltage fluctuations) of an electrical supply.

Line conditioners

A line conditioner protects your computer from the small fluctuations in voltage from an electrical supply. Most computers can handle this variation, called line noise, without problems. However, some electrical sources include more line noise than normal. Line noise can also be a problem if your computer is located near, or shares a circuit with, a device that causes electromagnetic interference, such as a television or a motor.

Some surge suppressors and uninterruptible power supplies include simple line-conditioning capabilities.

Uninterruptible power supplies

Use a standby uninterruptible power supply (UPS) to protect your computer from data loss during a total power failure. A UPS uses a battery to keep your computer running temporarily during a power failure and lets you save your work and shut down your computer. You cannot run your computer for an extended period of time while using only the UPS.

52Managing Your Computer