Sarthak and Wolfram,
Wolfram's comment reminded me of a significant observation. In our
laboratory, we operate a MAT 252 and a recently acquired MAT 253. I do
not know if some similar changes were made in the MAT 253 as the Delta-V.
However, our MAT 252 regularly has very low water backgrounds (i.e. 7-50mV
in the m/z 45 cup in CO2 configuration), whereas the MAT 253 regularly has
much higher water backgrounds (i.e. 1000-5000mV and higher! in the same
cup and configuration.) I beleive in this case, this discrepency may be
due to seals and or the type of CF inlet valve used on the system. Just
> Dear Sarthak,
> You are not alone with these questions. I too would be interested to learn
> what Delta-V users experiences are in this respect.
> Some Delta-V users have mentioned to me seeing rather high water
> background readings (higher than on other instruments in the same lab),
> something that may or may not be related to the source seal material.
> Another question would be if long-term use (> 3 years) would result in
> noticeable ion burn effects on the analyzer material?
> From: Stable Isotope Geochemistry [[log in to unmask]] On Behalf Of
> Sarthak Chakraborty [[log in to unmask]]
> Sent: 18 December 2007 04:45
> To: [log in to unmask]
> Subject: [ISOGEOCHEM] SS analyzer vs Al analyzer
> Dear All,
> I have a technical query which I like to get an answer from the users
> rather than from the manufacturer.
> The Thermo Fisher has introduced an aluminum alloy based analyzer instead
> of stainless steel in their Delta V Plus CF IRMS. I would like to know if
> it may affect the vacuum in general and particularly the long term
> performance of the machine.