Dear Chris,

> Does anyone know the purpose of the Baking switch (located to the right
> of the Source switch) on the Finnigan Delta S and 252 models?  On the
> Delta S, has anyone tried replacing a faulty switch?

Yes to the 1st and No to the 2nd.

The baking switch allows you to heat the source. A feature very
useful if you're into analysing SO2.

I found it quite handy to keep my source baked even while running
d13C analyses. Keeping the source hot minimizes CO2 peak tail
caused by CO2 "sticking" to the ceramic insulators of the DeltaS
ion source.

The difference between baking on or off can bee seen when looking
at the tail of CO2 reference pulses that ideally should be
rectangularly shaped. Without baking there is a small but
noticeable tail on the downside of the reference pulse signal.
However, with baking on, it all but disappears.

If the switch on your instrument is broken you're not missing out
much (unless of course you're running SO2 or your sample gas
contains "sticky" contaminants).

Hope this helps.


Best wishes,

                       Wolfram



***********************************
Dr. W. Meier-Augenstein, CChem, MRSC
Senior Research Fellow

University of Dundee
School of Life Sciences
Division of Molecular Physiology
Old Medical School, Small's Wynd
DUNDEE  DD1 4HN


Tel.: +44-(0)1382-34/5124, /4574, /4968
Fax:  +44-(0)1382-34/5514

e-mail: [log in to unmask]

URL1: http://www.dundee.ac.uk/biocentre/SLSBDIV6wma.htm
URL2: http://www.dundee.ac.uk/anatphys/wma/meieraug.htm
*******************************************************

NB Message is confidential and for recipient only: Unauthorized reading and copying
may result in legal action! Opinions expressed are those of the author and not the institution.
LEGAL NOTICE: Unless expressly stated otherwise, this message is confidential and
may be privileged.  It is intended for the addressee(s) only.  Access to this
e-mail by anyone else is unauthorized.  If you are not an addressee, any
disclosure or copying of the contents of this e-mail or any action taken (or not
taken) in reliance on it is unauthorized and may be unlawful. If you are not an
addressee, please inform the sender immediately.