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Daqarta
Data AcQuisition And Real-Time Analysis
Scope - Spectrum - Spectrogram - Signal Generator
Software for Windows Science with your Sound Card! |
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The following is from the Daqarta Help system:
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Features:OscilloscopeSpectrum Analyzer Signal Generator
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Applications:Frequency responseDistortion measurementSpeech and musicMicrophone calibrationLoudspeaker testMusical instrument tuningAnimal soundEvoked potentialsRotating machineryAutomotiveProduct testContact us about
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Spectrum Track Threshold Controls: Spectrum Dialog >> Track >> Threshold
This control allows you to limit the Track action to peaks above the threshold level you specify, to prevent spurious tracking of noise peaks when the desired signal is absent. The threshold is a single value, which is expressed according to the current Y-axis mode in volts, dB (if Y-log is active), or User Units. To the left of the control is a small box which shows the Spectrogram color corresponding to the threshold value. If you are setting the threshold for use with the Spectrogram Pitch Track option, it is usually much easier to adjust from the Spectrum display instead of the Spectrogram or Pitch Track display. Note that this threshold color is a function of the Spectrogram range and Color Palette as well as the Track Threshold setting. Note that this control value is saved to and loaded from MIDI Setup (.DQM) files. Loading a new MIDI Setup may change its value. Macro Notes: Important: The TrackThresh macro assumes the units of the current Y-axis mode. If Y-log is active, the units are expected to be in dB relative to full scale. If User Units is also active, the units might be in dB SPL, which will be very different values. For example, TrackThresh=60 will set 60 dB SPL if Y-log and User Units are active (assuming the units are Pa and the SPL button is active in the User Line dialog). But if User Units is off, this same command will set -60 dB since 0 dB is full-scale so a minus sign is always assumed. If Y-log is off and User Units is on, the same command will attempt to set 60 Pa (or 60 of whatever units are active). If both Y-log and User Units are off, it will attempt to set 60 volts. Due to these issues, it would be wise to precede a TrackThresh macro with macros to insure that the expected modes are active. You can also increment and decrement the threshold via macro. TrackThresh=>1 will increment by 1 dB in any dB mode. In linear modes the step size is that used by the little up/down arrows on the control itself, which is 1/32768 of the full-scale range. TrackThresh=>-1 will decrement by the same amount. Only single-step increments and decrements are allowed. See also Spectrum Cursor Track Dialog, Spectrum Control Dialog, Spectrogram / Pitch Track Controls |
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