Surges are common and costly. An IBM study found that every home or business is hit every day by at least one surge that measures 100 V and 1,000 V in intensity. The effects of a surge can be either very subtle or very dramatic. It all depends on the duration and intensity of the surge and whether or not the affected devices (computers, audio/video systems, and many more.) have adequate surge protection in place. Very subtle damage: surges in the 100 V range usually pass unnoticed. There is no visible indication that it occurred; however, when it does occur, it slowly degrade the internal electronic components in computers, TVs, and appliances. Any surge that is over the operating voltage of a device (120 V or 230 V, for example) will cause a small burst (or arc) of electrical current within the device. The device may continue to work, but repeated surges over time (and repeated arcs) will shorten the lifespan of the device and eventually cause it to fail. Other, less dramatic effects that surges have on a system are lockups and data corruption. Users may attribute the lockups or corruption to software compatibility issues, but many times, surges are the cause. Very dramatic damage: surges measuring several thousand volts may provide an audible clue that it occurred (a loud popping or frying sound). Smaller surges destroy internal circuitry slowly, over the course of several months. Larger surges, on the other hand, inflict the same damage, but in less than a millisecond. If the surge is long enough and strong enough, it may even heat up the internal electronic circuits to the point where they start to burn. In addition to the obvious costs needed to replace damaged devices, surges also cause lost productivity (when employees are idle in business environments) and loss of enjoyment (when home theater equipment and appliances are idle in home environments).