>Dear all,
>
>sorry for the message to manfred ending up on ISOGEOCHEM. But any
>suggestions would be most welcome! I thought I had seen most effects but am
>now splashing around looking for the solution!
>
>Paul
>
>Paul F. Dennis
>Head of Stable Isotope Laboratory
>School of Environmental Sciences
>University of East Anglia
>NORWICH NR4 7TJ
>UK
>
>Tel: 01603 593105
>Fax: 01603 507719
>email: [log in to unmask]
>
>-----Original Message-----
>From: Paul Dennis <[log in to unmask]>
>To: Stable Isotope Geochemistry <[log in to unmask]>
>Date: Friday, November 12, 1999 04:17
>Subject: N-VSMOW
>
>
>>Dear Manfred,
>>
>>I apologise for not writing earlier. The truth is we are in a period of
>>protracted problems with our water delta 18-O mass spectrometer. There is
>>something wrong with the micro dual-inlet that is proving very elusive to
>>track down. The syetm has bee taken apart, cleaned and re-built but still
>>with problems. These show up as a drift in both the measured delkta 45 and
>>delta 46 values with time. The drift is severe and about 5 to 10 per mille
>>over a 24 hour period! The patterns of change are not what would be
>expected
>>from a simple leak, or poor valve closure.
>>
>>Unfortunately also I have been away in New Zealand and so have not been
>able
>>to stand over my staff to ensure that they are working along the right
>>lines. Hopefully over the next few weeks I can sort things out and will be
>>able to report back to you with our measurements of VSMOW.
>>
>>The problems we are encountering now may partially expalin the
fractionally
>>heavier results we reported in the last round robin exercise. Once I
>>understand the cause of the effects I'll have a better idea if this is the
>>case.
>>
>>Best wishes,
>>
>>Paul
>>
>>Paul F. Dennis
>>Head of Stable Isotope Laboratory
>>School of Environmental Sciences
>>University of East Anglia
>>NORWICH NR4 7TJ
>>UK
>>
>>Tel: 01603 593105
>>Fax: 01603 507719
>>email: [log in to unmask]
>>
>>
>>
>