Peak Hold (Spectrum)

Peak hold averaging is performed at each individual order and retains the RMS peak levels of the averaged quantities from one FFT spectrum to the next.

Peak hold averaging is most useful when configuring a measurement system or when applying a limit to an order spectrum. The NI Sound and Vibration Measurement Suite computes peak hold averaging for order power spectra according to the following equation:

M A X ( X * ⋅ X )

where X is the complex FFT of the even-angle signal X, and X* is the complex conjugate of X.