Phase delay/time delay in two signals

[LynneMrk1]

Hi community, 

Is there any chance to clarify to me if the phase delay between two analog signals is the time delay? So if the time delay is known, can the data be shifted to account for the match of the signals?

Kind Regards,

Lynne

[Sam_Sharp]

Yes, the phase difference is essentially the same thing as the time difference.

If you look at the image below, there are two sinusoidal periodic signals and there is a phase angle difference between them. If you know the frequency of the signal then you can easily calculate the difference in 'time' instead of as an angle.

If you have a non-periodic/sinusoidal signal, then it doesn't really make sense to refer to the shift as a phase angle as the signal won't have a specified frequency etc. and would instead be referred to as a time delay.

[Norbert_B]

To elaborate Sams answer:

The time delay and the phase delay are not the same. However, it makes sense to talk about time and phase delay only for signals using the same frequency.

Let's look closer into this:

If you got two sines with 1Hz, a time delay of 100ms is a phase delay of 36 degree.

If the two sines have 2Hz, the time delay of 100ms would be a phase delay of 72 degree.

You see that a constant time delay represents a different phase delay depending on the frequency of the two signals. However, for a specific frequency, a given phase delay  represents a constant time delay and vice versa.

Norbert

[LynneMrk1]

So if the modules are not syncrhonised, the two sinewaves will be out of phase. If the time difference is known, they can match each other ?

I think I have seen couple of options to determine this phase difference or time difference. Using a scope, DIAdem phase option using FFT, or the following document. 

http://www.ni.com/example/26691/en/

Which one is the most suitable solution for an acquisition?

[Henrik_Volkers]

the correlation function?