Hello all:
After several days of trouble shooting, I finally found out
why the acquisition time is too long. Since many people are
interested in this subject, I would like to post my result here.
In VNMR, the parameter "d0" is a hiden pre-acquisition delay.
If there is a "delay(d0)" in the pulse sequence, the "time"
command only accounts for one d0 delay, but the acquisition
does two d0 delays. This is why the acqusition time is too long.
In the case of our gNnoe experiment, the parameters are:
d0=4, d1=1, nt=64, ni=96, phase=1,2
"time" command tells us the experiment will take 17:37:8 (one d0 delay).
The experiment took 31:14:46 to finish (two d0 delay).
After the experiment started. The "Remaining time:" in
the acquisition window is 44:55:33 (three d0 delay)
although the experiment did not take that long.
I do not know why VNMR does this, but this is what I observed.
Hope this information is helpful to you.
Weixing Zhang
-----Original Message-----
> From: Zhang, Weixing [mailto:Weixing.Zhang_at_stjude.org]
> Sent: Wednesday, July 31, 2002 1:43 PM
> To: AMMRL (E-mail)
> Subject: Acqisition time is too long
Hello all:
One faculty member in our department ran an H-N NOE experiment.
The "time" command showed that the experiment will take 17.5 hours,
but the experiment took more than 31 hours to finish. We use a
Varian Inova 600 (Solaris 8, VNMR 6.1C). Please let me know
if you have a clue what might have happened.
Thanks
Weixing Zhang, Ph.D.
Department of Structural Biology
St. Jude Children's Research Hospital
Voice: (901)495-3169
FAX: (901)495-3032
http://www.stjude.org/sb/wzhang.htm
http://www.stjude.org/sb/nmr.htm
Received on Thu Aug 08 2002 - 09:06:48 MST