A meter used to measure, calculate, and display the ratio of the peak power level to the time-averaged power level in a circuit, i.e., the peak-to-average ratio (p/a r. ) Note 1: A par meter is used as a quick means to identify degraded telephone channels. Note 2: A par meter is very sensitive to envelope delay distortion. The par meter may also be used for idle channel noise, nonlinear distortion, and amplitude-distortion measurements. Note 3: The peak-to-average ratio can be determined for many signal parameters, such as voltage, current, power, frequency, and phase.