Re: Simulated gas standards

[slaback@micf.nist.gov]

Yes, I have seen problems like that.  
Even from the same supplier.
I have also bought source sets where sources were
misidentified as to radionuclide.
I would spend the extra money all buy at least one
reference from one of the national labs, i.e., NIST,
Harwell, etc. so you can relate your other standards
to it. [note my possible bias on this point.]

Note that NIST 'traceability' usually means simply that
they own a NIST standard.  You are still are subject to
procedural/lab errors at the supplier.

Note that there is no program to establish 'traceability'
to NIST.  Indeed, the term is undefined.

There are several programs involving the distribution of
sources from NIST to various participating labs/companies
which give them the opportunity to check their operation
against certified NIST standards.  You might check to see
if your supplier is a participant in one of these.  You
might also ask your supplier how they achieve traceability.

If you want more specific information on these programs
contact Bert.Coursey@NIST.GOV (head of the division) or
J.Hutchinson@NIST.GOV (leader of the Radioactivity Group
which distributes standards).

A little risk adds spice to life.
Lester.Slaback@NIST.gov