In today’s world the need for up-to-date technology is everywhere; home, office and farm. Farmers are using specialized computer programs to make their operations more efficient and to predict necessary changes for the future. Homeowners are using their computers more and more to get news of interest to them, to organize their vacation plans and to shop at stores around the world.

One of the major sources of interruption to this technology is power interruption in the form of surges and spikes. According to the November 2004 issue of Successful Farming, a lightning strike is a less common culprit than spikes from air conditioners, refrigerators or a downed power line.

Cheryl Tevis, author of the Successful Farming article, states that most surge protectors continue to function as a power strip, even though the surge trap mechanism may have failed. While failing, surge protectors can reach high temperatures and start fires. At the minimum, an impaired unit leaves your computer vulnerable. For a few extra dollars you can buy a surge protector with an indicator light to show that it is still functioning as it should. Be sure the unit has an Underwriters Laboratory-approved label and that the product is listed as a transient voltage surge suppressor.

Three other important factors to look for in a surge protector, according to Ms. Tevis are:
Clamping voltage—indicates what level of voltage will cause the MOV to conduct electricity to the ground line. The lower the number, the better the rating.
Energy absorption/dissipation rating tells how much energy the protector can absorb before it fails. Look for a minimum of 200-400 joules. Even better is a rating of 600.
The surge protector should respond in less than a nanosecond. The faster the unit responds, the better it can protect your equipment. 

Surge Basics

On the website Howstuffworks.com we found the following information:

The main job of a surge protector system is to protect electronic devices from "surges." So if you're wondering what a surge protector does, the first question is, "What are surges?" And then, "Why do electronics need to be protected from them?"
A power surge, or transient voltage, is an increase in voltage significantly above the designated level in a flow of electricity. In normal household and office wiring in the United States, the standard voltage is 120 volts. If the voltage rises above 120 volts, there is a problem, and a surge protector helps to prevent that problem from destroying your computer.
 
To understand the problem, it is helpful to understand something about voltage. Voltage is a measure of a difference in electric potential energy. Electric current travels from point to point because there is a greater electric potential energy on one end of the wire than there is on the other end. This is the same sort of principle that makes water under pressure flow out of a hose -- higher pressure on one end of the hose pushes water toward an area of lower pressure. You can think of voltage as a measure of electrical pressure.

As we'll see later on, various factors can cause a brief increase in voltage.
When the increase lasts three nanoseconds (billionths of a second) or more, it's called a surge.
When it only lasts for one or two nanoseconds, it's called a spike.

If the surge or spike is high enough, it can inflict some heavy damage on a machine. The effect is very similar to applying too much water pressure to a hose. If  there is too much water pressure, a hose will burst. Approximately the same thing happens when too much electrical pressure runs through a wire -- the wire "bursts." Actually, it heats up like the filament in a light bulb and burns, but it's the same idea. Even if increased voltage doesn't immediately break your machine, it may put extra strain on the components, wearing them down over time. See how a surge protector works