Phase difference measurement of 2 different sine waves

[lplopez]

Hi,

I am currently working on measurement of phase difference of 2 sine waves over time. Sine1 has 10kHz frequency with 2uA amplitude while Sine2 has 200Hz with 10V amplitude. I am expecting to obtain the same result from the attached image. I also attached my initial work for your comments/suggestions. 

Thank you in advance,

-Lorenzo

[dsb@NI]

How do you define the phase difference between two sinusoids of different frequency?

[Henrik_Volkers]

Is your ADC in sync with both frequencies? 

Capture one or more periodes  (200Hz) and instead of a DFT I would apply a fit ..