Synchronicity of two signals I am trying to determine the synchronicity between two oscillating signals. I was attempting to do this by making use of the cross correlation between the two signals and looking at the maximum value. Is this a correct approach?

If so, which would be the better approach, to normalize the signals between 0 and 1 or to normalize the cross correlation?

I don't really mind about the difference in amplitude but I would like to see levels of synchronicity. Originally I thought to do cross correlation and look at the max of the graph however, I am not sure that this is the correct approach. I have also been looking at coherence of the spectra
Using cross-correlation and finding the peak is one way of finding the time delay between two signals.
This assumes that the two signals are periodic and have the same fundamental frequency.

When the two signals have close, but not equal fundamental frequency, the lag position of the maximum cross correlation value will change in time.  If the lag of the maximum does not change (and some thresholds are satisfied so you're not just cross-correlating two very weak signals with the same 60 Hz hum in the background), the two signals are synchronous.  If it changes slowly, that indicates the degree that the two signals have different frequencies.  If the lag requires T seconds for the lag to slide one period (which would be the distance between lags of maximum correlation) in one second, the two signals differ in frequency by 1 Hz.