Phase Shift Between two SIne Waves

[smoothdurban]

Hello,

I am trying to determine the phase shift between two sine waves of varying frequency.

Using the FFT function I am able to calculate the phase of each sine wave.

However I am uncertain how to calculate the phase shift between these two plots.

One of these plots is a generated sine wave with an increasing frequency between 0.2 and 5 Hz the other is a reaction to the command wave so it is a little erratic but does follow the commanded sine wave but with a lower amplitude.

Any ideas? 

I am using DIAdem 2012

[freighTrain]

smoothdurban,

Since you have the phase information for both waves, you can just take the difference between the two for the phase shift. I believe the FFT function's phase output is a plot of phase vs frequency. So, with the difference, you can look at the phase shift at specific frequencies.

[Brad_Turpin]

Hey Tim,

R&D responded with this excellent script for calculating the phase shift of two similar waveforms.

Brad Turpin

DIAdem Product Support Engineer

National Instruments

[smoothdurban]

Hey Brad

Looks good.

My only comment is I wish the comments were in english.

[Brad_Turpin]

Hi Tim,

Here's a version with English comments and a VIEW layout.

Brad Turpin

DIAdem Product Support Engineer

National Instruments