Hi Greg,
An engineer once told me that fluid flow through a tube is proportional to
the fourth power (r^4) of the internal radius. I would never recommend
doubling a capillary's size as a first experiment - let alone quadrupling
it. Perhaps there is a restriction somewhere else?


> -----Original Message-----
> From: Stable Isotope Geochemistry 
> [mailto:[log in to unmask]] On Behalf Of Greg Michalski
> Sent: Friday, 21 July 2006 5:18
> To: [log in to unmask]
> Subject: [ISOGEOCHEM] Delta V plus signal in conflo mode
> 
> My delta V seems to be pumping too good...In conflo I have 3 
> 10-7 torr so my signal for a 2 microliter of N2O (~100nmol) 
> is only ~1 volt which seems about an order of magnitude too 
> low...This is after changing the inlet from 50 micron to 100 
> micron capillary.  Ive cut ends off twice to ensure no 
> blockage, but still good vacuum.  Is going to 200 micron an 
> option anyone else has tried? 
>