Suzan,  It seems that every place has different requirements depending 
on the safety officers preference.  I our case we are required to keep 
the (necessarily small) bottle of SO2 in a hood then run a 1/16" line 
inside a 1/4" line to the Isoprime ref gas box.  The waste comes out of 
the ref gas box in another 1/16" line and goes back to the hood.  By 
keeping the output pressure of the SO2 tank about about 1 atm the SO2 
should not condense at room temperature.  On the ref gas box we never go 
above 0.5 atm and have had no problems even though it is not heated. So 
the solution to using a non-heated system seem to be to keep the 
pressure well below condensation point for SO2.   We are required to 
have an SO2 monitor, but as long as that doesn't go off or we cannot 
smell SO2 no other safety precautions are necessary.

We do leave the tank on at the 1 atm pressure continually, just turning 
up the pressure on the ref gas box from approximately 0.1 atm to 0.5 atm 
about a half hour prior to using the system.  This seems to work well.

Hope this helps, Paul.

On 1/7/2013 5:33 AM, Gilles St-Jean wrote:
> Hi Suzan
> You have a few options for this.
> 1) If you have a dual-inlet, then this is simple. Get some clean SO2 and add about 75 to 150 micromoles of SO2 to a side of the inlet and run for your ref pulses for a few days before you need to change for a fresh aliquot.
> 2) Depending on the version of interface you have:
> a) ConFlo II: You will need to either replace one of the brass regulators for a stainless steel one with a stick-on heater and supply (I don't know the wattage used), or build a separate box with a SS regulator and heater and attach its own capillary to the ConFlo II via a dual hole ferrule to one of the existing Ref actuators.
> b) ConFlo III: Use the stainless steel regulator along with the heater power supply provided for this regulator.  In the ConFlo III, it is either Ref1 or Ref2 (I forget, see manual)
> c) ConFlo IV: It is clearly marked which regulator to use and came with a heater power supply as well.
> You will need to vent the SO2 to a hood with a nederman arm or similar
> Best regards
> Gilles
> Gilles St-Jean
> Scientifique en Recherche et Développement / Research and Development Scientist
> Université d'Ottawa / University of Ottawa
> Sciences de la Terre / Earth Sciences
> Pavillon / MacDonald / Hall
> 150 Louis Pasteur, MCD-317
> Ottawa, Ontario, Canada K1N 6N5
> Tel: 1-613-562-5800 xt 6830 (Bureau / Office)
> Téléc. / Fax: 1-613-562-5192
> Courriel / E-mail: [log in to unmask]
> "You can please some of the people all of the time, and all of the people some of the time, but you can not please all of the people all of the time". Mod. from Abraham Lincoln (attributed); 16th US president (1809 - 1865)
> -----Message d'origine-----
> De : Stable Isotope Geochemistry [mailto:[log in to unmask]] De la part de Suzan Verdegaal
> Envoyé : 7 janvier 2013 06:27
> À : [log in to unmask]
> Objet : [ISOGEOCHEM] SO2 reference gas installation
> Dear all,
> We are trying to set up the Flash to be able to measure d34S for a long time. First attempts gave good results, but since we now have to find a permanent solution for having SO2 in our lab we are struggling. The person who is responsible for handing and installing gasses suggests a very expensive setup. This will make it possible to flush the whole system (from gass-bottle to Conflo) automatically. We are now wondering if this is really necessary and if there maybe is a standard method for using SO2 as a ref-gas.
> It would be really helpful to hear the experiences of other users of SO2 gas.
> Thanks in advance.
> Suzan
> Lab Manager Stable isotope lab.
> Faculty of Earth and Life sciences
> Free Universtity Amsterdam

Mr. Paul D. Brooks, Spectroscopist,
Dept. Integrative Biology MC3140
1005 Valley Live Sceince Building,
UC Berkeley, CA 94720-3140.

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