Dear Rick and all others interested,
the magnet power supply is a primary switched type with a small 
transformer that changes frequency when the current through the coils is 
altered. If our ears could hear frequencies easily between about 12000 
and 25000 Hertz you would hear the sound change with every current (and 
hence mass) alteration. The frequencies have been selected so that they 
cannot be heard easily, but a high pitch whining noise can still 
sometimes be heard due to unintended resonance effects. So, its not your 
cat, a poor bat or an evil ghost that has impersonated your Delta Plus. 
Its the machine itself, trying to tell you in its own way what its doing.
Regards   Willi

Simon Poulson wrote:
>> Hello all,
>> Might anyone know why my Delta Plus Advantage emits a high-pitch 
>> whine when running sulfur by EA-IRMS???  It does not do this for any 
>> other gas configuration.
>> I will accept humorous answers as well as bona-fide truths.
>> Cheers,
>> Rick
>
>
> Rick,
>
> Could it be that your magnet power supply is singing to you?  The 
> magnet current will be highest for SO2 vs. any other configuration, so 
> maybe that explains the higher current is causing the whine?
>
> In any case, good luck with the troubleshooting.
>
> Cheers,
> Simon
>

-- 
.....................................................................
Willi A. Brand, Stable Isotope Laboratory      [log in to unmask]
Max-Planck-Institute for Biogeochemistry (Beutenberg Campus)
Hans-Knoell-Str. 10, 07745 Jena, Germany      Tel: +49-3641-576400
P.O.Box 100164,      07701 Jena, Germany      Fax: +49-3641-577400
http://www.bgc-jena.mpg.de/
http://www.bgc-jena.mpg.de/service/iso_gas_lab/
.....................................................................