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What are the Output Units of FFT-based VIs?

Primary Software: LabVIEW Development Systems>>LabVIEW Professional Development System
Primary Software Version: 8.2
Primary Software Fixed Version: N/A
Secondary Software: LabVIEW Development Systems, LabWindows/CVI Development Systems

Problem: I am using one of the FFT VIs in LabVIEW or FFT functions in CVI and I want to know what the output units are.

Solution:

The following table displays the output units and scale factors that the LabVIEW FFT-based VIs use.

VI Non-DC Unit
(k>0)		 DC Unit
(k=0)		 Sided Non-DC Scale Factor DC Scale Factor Phase Unit
FFT V V Double N/2 N radians
Power Spectrum Vrms2 V2 Double 1/2 1 —
Auto Power Spectrum Vrms2 V2 Single 1 1 —
Amplitude and Phase Spectrum Vrms V Single 1 1 radians
FFT Power Spectrum Vrms2 V2 Single 1 1 —
FFT Power Spectral Density Vrms2/Hz V2/Hz Single 1 1 —
FFT Spectrum (Mag-Phase) Vrms V Single 1 1 radians/degrees
FFT Spectrum (Real-Imag) Vrms V Single 1 1 radians/degrees


Related Links: LabVIEW 8.2 Help: Output Units for FFT-Based VIs


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Report Date: 06/22/2006
Last Updated: 10/20/2006
Document ID: 3YLGIEW1

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