Dear Sulfur Isotpe Analysts,

I received the Rep. No.45 by Max Coleman from Natural Environment
Res.Council, which I acknowledge gratefully.
However, I would like to aware those who want to apply formulae
derived in this report that the formulae reffer to configuration of
the dual colletor which was common in former times, but not in the
new spectrometers having separate Faraday cups for individual
ion bams.For example, the  most useful formulae are :

d34 = 1.094 d66 - 0.089 d18 (for collection 64+65 ion beams)
d34 = 1.089 d66 - 0.089 d18 (for colletion of single beams)

Considering new absolute sulfur and oxygen isotope ratios (see Ding
et al., 1998, Abstracts of ICOG-9,page33 for 34/32 and for oxogen
ratios see Makishima et al.,1987, Mass Spectrosc.,vol.35,64) one
obtains a bit larger isobaric corrections:

d34 = 1.101 d66 -  0.096 d18 (for 64+65 and 66 collection)
d34 = 1.096 d66 -  0.096 d18 (for 64  and 66 collection)

I hope that Max will extend his Rep. No.45 into single beam
collector system and update the calculation of isobaric  corrections
by including new absolute isotope ratios.

With geetings from Poland,

                                         Stan