The solution is:
take the NC_proc paramters for all spectra from the "procs" file in the
processing dir, and multiply each spectrum by the corresponding
2^(NC_proc). This is at least what I do, and it works.
Regards
Alexej Jerschow
Miquel Cabanas. BBM-UAB writes:
> hi all,
>
> I have a problem with the scaling of intensities in exported 1R spectra
> that I don't seem to be able to fix.
>
> Few weeks ago I recorded a bunch of 1D files (ca 250) to measure diffusion
> coefficients in several samples, I used an ARX-400, with XWinnmr 1.2 running
> on an Aspect-1.
>
> So far so good, at first glance all the experiments seemed to work ok. Lazy
> as I am I did not want to process all spectra one-by-one, so I wrote a Matlab
> program that reads the files in, process them and reports some tables and
> graphics. Disappointingly, after getting almost all spectra processed (I
> discarded processing the ones we had run for testing purposes) the conclusion
> was that no-one of the experiments had worked as desired... well it seemed I
> was going to have to re-do all exps once more. But before doing so I've
> thought it was worth processing the experiments I knew they had worked, and
> here is when my problem happens:
>
> 1. the intensities reported on-screen by XWinnmr and those I can read
> in the '1r' file do not match (the on-screen intensities decay with
> increasing values of 'b')
>
> 2. I've discarded I'm messing them when reading the file because they are
> the same intensities I get when exporting the '1r' file as JCAMP-DX
> file
>
> 3. funny enough (not really), the ratio between intensities reported on-
> screen and those in the '1r' file gives some interesting values
> (see the last column)
>
> -----------------------------------------------------------------
> maximum intensity
> G_eff ---------------------------
> <expno> (G/cm) on-screen JCAMP-DX[1] ratio
> -----------------------------------------------------------------
> 21 4.0 3.41743e+07 2.73394e+08 8
> 22 6.0 2.97554e+07 4.76086e+08 16
> 23 7.5 2.52609e+07 4.04175e+08 16
> 24 9.0 1.85172e+07 5.92549e+08 32
> 25 10.0 1.47869e+07 4.73181e+08 32
> 26 2.5 3.53060e+07 2.82448e+08 8
> -----------------------------------------------------------------
> [1] match the values in the '1r' files as read with Matlab
>
> I'm totally clueless. I'm using the same acquisition parameters throughout
> all experiments, so there is nothing that could be explained by a change
> in RG, NS, etc. ,
>
> -why this scaling factor?
>
> -where do I find the scaling factor I must apply to retrieve the
> correct(?) intensities?
>
> If anyone out there knows the answer I'll be glad to know.
>
> Thanks in advance,
>
> Miquel
>
>
> Miquel E Cabanas ---------------------------------------------------
> SeRMN & BBM - Universitat Autonoma de Barcelona, Catalunya - Spain
>
> MRUI url ------- http://www.mrui.uab.es/mrui
> ------------------------------------------o-oo--ooo---ooo--oo-o-----
>
>