This is a standard for definitions used for measurement of electric power quantities under sinusoidal, nonsinusoidal, balanced, or unbalanced conditions. It lists the mathematical expressions that were used in the past, as well as new expressions, and explains the features of the new definitions. This standard is meant to provide organizations with criteria for designing and using metering instrumentation. New IEEE Standard - Superseded. This is a standard for definitions used for measurement of electric power quantities under sinusoidal, non-sinusoidal, balanced, or unbalanced conditions. It lists the mathematical expressions that were used in the past, as well as new expressions, and explains the features of the new definitions.