Hi,

what do you want to lower into the dewar, a capillary? Get yourself an 
adequate pneumatic piston (e.g. from clippard). Attach a strip of aluminium 
to it, and attach a 1/16" or 1/8" loop to the aluminium strip using Swagelok 
fittings (port connectors). Now you will have a loop that can move up and 
down, but it will also rotate. This can be fixed by covering the dewar with 
styrofoam, which will have a slit in it to provide the loop with guidance, or 
a similar setup.

Cheers

Peter


On Tuesday 27 June 2006 11:13, Shelley Kunasek wrote:
> I'd like to automate a continuous flow EA/IRMS system to have a liquid
> nitrogen trap lower into a dewar and then lift out at the right time.  We'd
> like to basically build this simple component of a precon or a gas bench
> without having to buy a whole precon or gas bench.  Has anyone had
> experience building that type of setup?
>
> Thanks
>
> Shelley Kunasek
>
> University of Washington
> Department of Earth and Space Sciences
> 206-543-6223
> [log in to unmask]

-- 
============================================================
Dr Peter Franz

National Institute for Water and Atmospheric Research (NIWA)
301 Evans Bay Pde
Private Bag 14901
Kilbirnie
Wellington
New Zealand

Ph : 	++64-(0)4-386-0506
Fax: 	++64-(0)4-386-2153
Mobile:	++64-(0)211-109304

Email: [log in to unmask]
Website: www.niwa.co.nz
============================================================