Hi everyone,

I've got a small but annoying (and probably very simple) problem with the
O18 ratios of SMOW and PDB and the relationship between gases calculated
upon these.  If I use absolute ratios to convert from PDB to SMOW, nothing
seems to work...

The values I have are SMOW: 2005.2 and PDB: 2079.

The standard relationship we use to convert from gases with respect to PDB
and SMOW is Delta(SMOW)=1.03091 * Delta(PDB) + 30.91, implying that PDB is
30.91 permil heavier than SMOW.

My problem is that I can't get any calculation with 2005.2 and 2079 to come
up with a value of 1.03091, even allowing for the PDB ratio to be that of
the gas extracted from PDB dissolved in Phosphoric at 25C.

It's got to be easy, but I can't suss it out myself, so any help would be
hugely appreciated.

Thanks in advance,

Andrew
--
Andrew Tait
SURRC
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