Owning Palette: Sound Level VIs

Requires: Sound and Vibration Toolkit

Computes the running equivalent continuous sound level (Leq) of scaled signal [EU] . scaled signal [EU] should have a zero DC component. Wire data to the scaled signal [EU] input to determine the polymorphic instance to use or manually select the instance.

The Sound Level VIs return respective sound pressure levels in dB rms relative to the reference. By default, a sound pressure level of 20 uPa rms is used as the reference for conversion to dB. In contrast, peak and peak-to-peak sound pressure levels are referenced to 20 uPa pk.

Details

SVL Running Leq Sound Level (1 Ch)SVL Running Leq Sound Level (N Ch)

SVL Running Leq Sound Level (1 Ch)

scaled signal [EU] specifies the scaled signal expressed in the selected engineering units. To obtain a properly scaled signal, you can use the SVL Scale Voltage to EU VI or define a virtual channel in National Instruments Measurement & Automation Explorer (MAX).
t0 specifies the start time of the waveform.
dt specifies the time interval in seconds between data points in the waveform.
Y specifies the data values of the waveform.
integration time specifies the duration over which the computation occurs in seconds. The default is 1.00. integration time is rounded to a duration corresponding to an integer multiple of the duration of a single block of time-domain data. The actual value used by this VI is returned in actual integration time .
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
restart averaging specifies if the selected averaging process has to be restarted. The default is FALSE. When you call this VI for the first time, the averaging process restarts automatically.
running Leq sound level [dB EU] returns the running equivalent continuous sound level (Leq) in decibels.
unit label returns the selected engineering units.
actual integration time [s] returns the actual duration over which the computation occurred in seconds.
error out contains error information. This output provides standard error out functionality.

SVL Running Leq Sound Level (N Ch)

scaled signals [EU] specifies the scaled signals expressed in the selected engineering units. To obtain a properly scaled signal, you can use the SVL Scale Voltage to EU VI or define virtual channels in National Instruments Measurement & Automation Explorer (MAX).
t0 specifies the start time of the waveform.
dt specifies the time interval in seconds between data points in the waveform.
Y specifies the data values of the waveform.
integration time specifies the duration over which the computation occurs in seconds. The default is 1.00. integration time is rounded to a duration corresponding to an integer multiple of the duration of a single block of time-domain data. The actual value used by this VI is returned in actual integration time .
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
restart averaging specifies if the selected averaging process has to be restarted. The default is FALSE. When you call this VI for the first time, the averaging process restarts automatically.
running Leq sound levels [dB EU] returns the running equivalent continuous sound levels (Leq) in decibels.
unit labels returns the selected engineering units for each channel.
actual integration time [s] returns the actual duration over which the computation occurred in seconds.
error out contains error information. This output provides standard error out functionality.

SVL Running Leq Sound Level Details

The SVL Running Leq Sound Level VI requires a continuous input data stream. An internal mechanism automatically restarts the filters if the input data flow is not a continuous flow.

You can attenuate the DC component with hardware AC-coupling filters and with software high-pass filters. A new running Leq value is returned each time you call this VI. A shift register internal to this VI maintains the result of past runs. The new result is an averaged level that includes the latest block of samples and the level history in the specified integration time.