Thanks, that's great. (I guess there's probably a Bruker manual that
probably specifies all of this but I don't have a copy of it.) I'll have
to see how/if we can work that into the current Analysis. (It will
definitely be in the new version.)
Wayne
On Wed, 13 Feb 2008, Dr Horst Schirra wrote:
> Hi Wayne and Mark,
>
> the parameter you want is called NC_proc and will be in the procs
> processing parameter file for each spectrum.
>
> The parameter is a log2 scale, i.e.:
>
> NC_proc=2 spectrum has been scaled up by factor of 4
> NC_proc=1 spectrum has been scaled up by factor of 2
> NC_proc=0 scaling of spectrum intensity unchanged
> NC_proc=-1 spectrum has been scaled down by factor of 2
> NC_proc=-2 spectrum has been scaled down by factor of 4
>
> etc.
>
> In my relaxation measurements, I typically encounter NC_proc values
> between -2 and -6, just as an indication...
>
> The true intensity of any data point is then
> int_corr= bruker_raw_int * (2 ^ NC_proc)
>
> Cheers,
>
> Horst Joachim Schirra
>
> PS: Can you tell, I had to fiddle with that *a lot*? ;)
> ----------------------------------------------------------------
> / Dr. sc. nat. Horst Joachim Schirra Phone: (+61)7/3346-2021 /
> / Queensland Smart State Fellow Fax: (+61)7/3346-2101 /
> / Institute for Molecular Bioscience /
> / University of Queensland email: [log in to unmask] /
> / Brisbane QLD 4072, Australia http://www.uq.edu.au/~uqhschir /
> ----------------------------------------------------------------
>
>
>
> ----- Original Message -----
> From: Wayne Boucher <[log in to unmask]>
> Date: Tuesday, February 12, 2008 9:03 pm
> Subject: Re: problem with T1 series
> > Hello,
> >
> > This is a (relatively recently) known problem. Bruker stores
> > everythingas ints, not floats, so quite sensibly has a multiplier
> > specified (which
> > we discovered when someone else had a problem similar to the below).
> > This requires us to add a scale to the C world, passed down from the
> > Python world, so that the data comes back correctly. For
> > contouring there
> > is a fix already available (setting the spectrum scale, although
> > I'll have
> > to remind myself where this scale is hiding in the Bruker files).
> > Thisfix is not available for the rates analysis but I guess could
> > be (if Tim
> > thinks it makes sense).
> >
> > Wayne
> >
> > On Tue, 12 Feb 2008, Mark Pfuhl wrote:
> >
> > > I tried to extract T1 values from a standard T1 experiment. The
> > spectrum was
> > > recorded and processed with Topspin and loaded straight into
> > analysis. In
> > > Topspin I got the expected decay but in analysis I have a
> > sawtooth pattern
> > > that has no resemblance to the original data.
> > > The sawtooth appearance suggests that the exponent of the
> > intensities is
> > > lost somehow in loading it into analysis.
> > > Is there something wrong or do I need to load the spectra in a
> > specific way
> > > if I want to maintain correct intensities?
> > > thanks,
> > > mark
> > >
> >
>
|