The causes and impacts of power disturbances on both sides of the user-utility interface are discussed, and the results of power quality surveys are reviewed. Desirable attributes of monitoring equipment are discussed along with approaches that can be taken by the electric utilities to improve the quality of the power delivered to customers. Users of sensitive devices, such as computers and health care equipment, are given information on power quality improvement equipment, such as uninterruptible power supplies. Includes a glossary.