Re: Room Preparation for NMR instrument

jim breeyear (jbreeyea@zoo.uvm.edu)
Tue, 01 Dec 1998 14:35:38 -0500

HI,
As it turned out with our installation, the most obvious problem was
floor vibration causing some spikes near the peaks. The vibration is
caused from an air conditioner. The air cushions removed most of the
noise. I am trying to get the fans balanced but those things seem to
take time. We have ICP , Xray , mass spec, local radio stations , etc
and dont see any intefering signals. There was some power supply
sidebands on the spectra but those were removed by shielding the power
supply with a metal plate. Good luck.
Jim

Ulrike Werner-Zwanziger wrote:
>
> Dear Colleagues,
>
> we are preparing an area for a 200 MHz NMR spectrometer for our
> chemistry teaching laboratory. Since it has to go cheap, I would like to
> ask your opinion on the necessity of the following items. In particular
> I would like to know:
>
> -- Concerning fluorescent lights, do they cause problems? Which
> frequencies do they typically emit. (In the room I could detect 160 MHz,
> 125 MHz, 80 MHz, 64 MHz on the oscilloscope mostly related to a weather
> station.) Are these frequencies clean enough to cause identifiable
> spikes or do they vary? Is it worth the money to install a special
> low-RF light ballast (on 15 lights in the room)?
>
> -- Do you regard a separate earthing cable aside from the earth in the
> normal three prong connectors a worthwhile investment?
>
> -- Could you please comment on the effects to consider from conduits and
> piping in the ceiling close to the magnet.
>
> If there is interest, I can post a summary of comments later.
> Thank you very much.
>
> Ulrike
> --
> Ulrike Werner-Zwanziger
> Department of Chemistry
> Indiana University
> Bloomington, IN 47405
>
> Phone: (812) 856-4629
> Fax: (812) 855-8300
> WWW: http://nmr.chem.indiana.edu/~uwz

-- 

=+=+=+=+=+=+=+=+=+=+=+=+=+=+= Jim Breeyear Univ of Vermont Manager, Inst. Chemistry Dept.