You are here: NI Home > Support > Product Reference > Manuals > Sound and Vibration Measurement Suite 6.0 Help

You can use the following strategies to obtain the spectrum of an integrated signal:

• Perform the integration in the time domain before computing the spectrum.
• Compute the spectrum before performing the integration in the frequency domain.

The following block diagram demonstrates the implementation of the strategies used to obtain the spectrum of an integrated signal.

The highpass cutoff frequency parameter of the SVL Integration VI is wired with a constant of 10 Hz. The SVL Integration (frequency) VI does not have a highpass cutoff frequency parameter. Instead, the SVL Integration (frequency) VI sets the DC component of the integrated signal to zero if the spectrum scale is linear, or to negative infinity (–Inf) if the spectrum scale is in decibels.

The following front panel shows the results of integrating in the time and frequency domains.

The power spectrum is computed after the time-domain integration filters settle. The frequency-domain integration scales the spectrum at each frequency line. No settling time is necessary for the frequency-domain integration because integration filters are not involved in the frequency-domain integration.

Perform frequency-domain integration in the following situations to maximize performance:

• When the integrated signal is not needed in the time domain
• When spectral measurements are performed