What is it?
The term "line noise" refers to random fluctuations-electrical impulses that are carried along with standard AC current. Turning on fluorescent lights, laser printers, working near a radio station, using a power generator, or even working during a lightening storm can all introduce line noise into systems.
What can it do?
Line noise interference can result in many different symptoms depending on the situation. Noise can introduce glitches and errors into programs and files. Hard Drive components can be damaged. Televisions and computer screens can display interference as "static" or "snow," and audio systems experience increased distortion levels.
What can be done?
Surge suppressors, Line conditioners and UPS units include special noise filters that remove or reduce line noise. The amount of filtration is indicated in the technical specifications for each unit. Noise suppression is stated as Decibel level (dB) at a specific frequency (kHz or MHz). The higher the dB, the greater the protection.
Be wary of "surge/noise suppressors" that don't provide this information. Some surge suppressors (Such as the Tripp Lite Isobar suppressors) take noise suppression to a new level with Isolated Filter Banks. These special banks prevent line noise generated from one device from traveling through the surge suppressor to interfere with other equipment.
Using a laser printer (a notorious source for line noise) connected to the same suppressor that powers a computer will not endanger the computer.