Obviously, actual usage will determine how long a cylinder will last.  That being said, even if running samples on a TC/EA-IRMS every other day, both H2 and CO cylinder (L size) last us at least one year, the CO cylinder may even last 2 years (with a septum on the bleed capillary inside the ConFlo).

Please, note, we do not use CH4; we use H2 as monitoring gas for 2H analysis.

The above information is based on all gas plumbing being stainless steel, i.e. both tubing and connectors (unions, T-pieces etc.).  Appendix II.A in Part II of the book "Stable Isotope Forensics" deals with all aspects of setting up an IRMS lab; II.A.5 deals specifically with gas supply.

https://onlinelibrary.wiley.com/doi/book/10.1002/9781119080190


-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of khaled EL hawari
Sent: 07 December 2018 09:36
To: [log in to unmask]
Subject: [ISOGEOCHEM] carbone monoxide and methane cylinder consumption

Dear All

hope your doing well

we are working on the implementation of new IRMS laboratory. and we are new in this field i would like to ask you how much offen carbone monoxide and methane gas cylinder you change in your lab for analyzing H and oxygen stable isotopes

because i found that running cost for these gases is expensive

can you pls share with me your experience of that issue

regards

----------

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