Thread: time domain analysis from pressure sensor

dear all,
i am now detecting the leak from pipeline. i am a very new user for matlab. i am now facing some difficulties to do time domain analysis from the pressure sensor. i have already done for frequency domain analysis but still need to analyse with time domain.
here is my frequency domain analysis. pls help me how to write the code for time domain analysis. my final result is intended to detect the pipe when it will leak as exact as i can.

directory = cd;
> > c = [0.0018441793 34.3574964587]; % stn-a
> > filelist = ls(['STN_a*.raw']);
> > allpressure =[];
> > fs = 1000;
> > for ii= 252:253
> > prid = fopen(char(filelist(ii,));
> > pressure = fread(prid, inf, 'int16');
> > fclose(prid);
> > allpressure = [allpressure; pressure];
> > end
> > t = linspace(0,length(allpressure)/fs,length(allpressure));
> >
> > figure;
> > plot (t,allpressure);
> > xlabel('time (sec)');
> > ylabel ('pressure (psi)');
> > specgramdemo(allpressure,1000);

thanks in advance!
poe

Originally Posted by poepoe

dear all,
i am now detecting the leak from pipeline. i am a very new user for matlab. i am now facing some difficulties to do time domain analysis from the pressure sensor. i have already done for frequency domain analysis but still need to analyse with time domain.
here is my frequency domain analysis. pls help me how to write the code for time domain analysis. my final result is intended to detect the pipe when it will leak as exact as i can.

directory = cd;
> > c = [0.0018441793 34.3574964587]; % stn-a
> > filelist = ls(['STN_a*.raw']);
> > allpressure =[];
> > fs = 1000;
> > for ii= 252:253
> > prid = fopen(char(filelist(ii,));
> > pressure = fread(prid, inf, 'int16');
> > fclose(prid);
> > allpressure = [allpressure; pressure];
> > end
> > t = linspace(0,length(allpressure)/fs,length(allpressure));
> >
> > figure;
> > plot (t,allpressure);
> > xlabel('time (sec)');
> > ylabel ('pressure (psi)');
> > specgramdemo(allpressure,1000);

thanks in advance!
poe

Not enough information, what time domain analysis do you want to do?

CB

i'm sorry for my incomplete message. time domain analysis for fourier transform and wavelet transform.

thanks!
poe