Time delay estimation of two sensor signals I have two sensors which are placed around 30  to 40 cm apart , both of them measure the same   signal say 'lambda signal'. so there is a delay in the measurement of the signal from the second sensor. During the travel there is some noise added to the signal. What are the procedure that I can use to calculate the time delay between them. 
According to my knowledge if I cross correlate both signals, the peak gives me the delay value of the second, but this is not working. Is there any other methods to find the time delay between eachother. Please guide me as I am new to signal processing.![Part of the signals][1]![Another part signal][2] 

link: https://docs.google.com/open?id=0BzT9Q3HfpmDKZERPSGJoTEFyTzA
link : https://docs.google.com/open?id=0BzT9Q3HfpmDKeVhMSnZLa3BfMjQ
Thanks in advance.
Naveen
Comment: As a new user I am not allowed to add a comment to your question - hence this approach.

You mention that you do get a peak from the cross-correlation but that the lag estimation is incorrect.  This implies that you know the correct result - is from a calibration signal or ..? And what is the lag roughly?

Could you explain what the signals look like (sinusoidals for example)?  Also what is the SNR, sequence length, sampling frequency? Have you filtered the signals before sampling - if so how?

If the offset is incorrect it might be related to insufficient time resolution. Using a sampling frequency $f_s$ means that your time resolution is $T_\mathrm{s}=\frac{1}{f_\mathrm{s}}$.  If this time resolution is not sufficiently small you may get an estimate that does not agree with your expectations.

There may be other techniques but this depends on the signals you have - and also if you for example know that the lag is always a fraction of a period time of a periodic signal. Some more details could help with this.