SVT SINAD VI

SVT SINAD VI

Owning Palette: Tone and Distortion VIs

Requires: Sound and Vibration Toolkit

Performs a signal in noise and distortion (SINAD) analysis, including measuring the fundamental tone, and returns the detected fundamental frequency, detected fundamental amplitude, and SINAD level in dB. Total harmonic distortion plus noise (THD + N) is the negative of SINAD in dB. Wire data to the scaled signal [EU] input to determine the polymorphic instance to use or manually select the instance.

The following formula calculates SINAD:
SINAD = sqrt(F^2 + N^2 + H^2) / sqrt(H^2 + N^2)
where F is the fundamental tone RMS level, N is the noise RMS level, and H is the harmonic RMS level.

Example

SVT SINAD (Time) (1 Ch)

	desired units specifies the engineering units of the returned measurements. SINAD units specifies the unit for SINAD. 0 dB (default) 1 Linear ratio 2 % detected fundamental amplitude units specifies the units for the amplitude of the detected fundamental tone. 0 EU rms (default) 1 EU peak 2 EU peak-peak
	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.
	frequency range specifies the frequency band of analysis. start frequency specifies the lowest frequency of interest for the analysis band in hertz. Specify a value of –1 to select f0 as the minimum frequency of interest. The default is –1.00 Hz. stop frequency specifies the highest frequency of interest for the analysis band in hertz. The valid range is between 0 and the Nyquist frequency. Specify a value of –1 to select the highest frequency as the maximum frequency of interest. The default is –1.00 Hz.
	advanced span [Hz] specifies a frequency span centered at the identified fundamental frequency in which noise and spurious components are ignored for the measurement. Specify a value of 0 if the frequency is known and time invariant. Specify a value of –1 to permit the measurement to automatically compute the minimum frequency span suitable for the time-domain window applied to the signal. The default is –1 Hz.
	error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
	expected fundamental frequency specifies the expected frequency of the fundamental tone in hertz. Use expected fundamental frequency when the fundamental tone is not the largest amplitude component of the input signal. The default is –1.00 Hz.
	unit labels returns the unit label for each member of desired units. SINAD unit label returns the unit label for SINAD. detected fundamental amplitude unit label returns the unit label for the amplitude of the detected fundamental tone.
	complex spectrum returns the complex form of the computed spectrum. f0 returns the start frequency, in hertz, of the spectrum. df returns the frequency resolution, in hertz, of the spectrum. complex spectrum returns the complex form of the computed spectrum.
	SINAD returns the measured signal in noise and distortion (SINAD), which is defined as the ratio of the RMS energy of the input signal to the RMS energy of the input signal less the RMS energy of the fundamental tone.
	error out contains error information. This output provides standard error out functionality.
	detected fundamental amplitude returns the amplitude of the detected fundamental tone. High amplitude means an increase in the rate of energy transport, resulting in a louder sound.
	detected fundamental frequency [Hz] returns the frequency of the detected fundamental tone in hertz. High frequency means a short wavelength, resulting in a higher pitch.

SVT SINAD (Spectrum) (1 Ch)

	desired units specifies the engineering units of the returned measurements. SINAD units specifies the unit for SINAD. 0 dB (default) 1 Linear ratio 2 % detected fundamental amplitude units specifies the units for the amplitude of the detected fundamental tone. 0 EU rms (default) 1 EU peak 2 EU peak-peak
	complex spectrum specifies the complex form of the computed spectrum. f0 specifies the start frequency, in hertz, of the spectrum. df specifies the frequency resolution, in hertz, of the spectrum. complex spectrum specifies the complex form of the computed spectrum.
	frequency range specifies the frequency band of analysis. start frequency specifies the lowest frequency of interest for the analysis band in hertz. Specify a value of –1 to select f0 as the minimum frequency of interest. The default is –1.00 Hz. stop frequency specifies the highest frequency of interest for the analysis band in hertz. The valid range is between 0 and the Nyquist frequency. Specify a value of –1 to select the highest frequency as the maximum frequency of interest. The default is –1.00 Hz.
	advanced span [Hz] specifies a frequency span centered at the identified fundamental frequency in which noise and spurious components are ignored for the measurement. Specify a value of 0 if the frequency is known and time invariant. Specify a value of –1 to permit the measurement to automatically compute the minimum frequency span suitable for the time-domain window applied to the signal. The default is –1 Hz.
	error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
	expected fundamental frequency specifies the expected frequency of the fundamental tone in hertz. Use expected fundamental frequency when the fundamental tone is not the largest amplitude component of the input signal. The default is –1.00 Hz.
	unit labels returns the unit label for each member of desired units. SINAD unit label returns the unit label for SINAD. detected fundamental amplitude unit label returns the unit label for the amplitude of the detected fundamental tone.
	complex spectrum returns complex spectrum unchanged. f0 returns the start frequency, in hertz, of the spectrum. df returns the frequency resolution, in hertz, of the spectrum. complex spectrum returns the complex form of the computed spectrum.
	SINAD returns the measured signal in noise and distortion (SINAD), which is defined as the ratio of the RMS energy of the input signal to the RMS energy of the input signal less the RMS energy of the fundamental tone.
	error out contains error information. This output provides standard error out functionality.
	detected fundamental amplitude returns the amplitude of the detected fundamental tone. High amplitude means an increase in the rate of energy transport, resulting in a louder sound.
	detected fundamental frequency [Hz] returns the frequency of the detected fundamental tone in hertz. High frequency means a short wavelength, resulting in a higher pitch.

Example

Refer to the One Shot Gain Phase and Distortion (DAQmx) VI in the labview\examples\Sound and Vibration\Audio Measurements directory for an example of using the SVT SINAD VI.