Hello Shelley,
What will you be using to control the timing and pneumatic piston activation? 
There are a wide variety of low-cost pneumatic switches and electronic timers available, as well as non-rotating pneumatic pistons. We've used SMC's C85 series http://www.smcetech.com/CC_host/pages/custom/templates/smc_v2/prodtree_branch_group_2.cfm?cc_nvl=((CC,smc,ACT,Node_9291)) 
They can be ordered from your local industrial machinery suppliers (check the smctech.com homepage for distributors) at a decent price (87 to 105 USD), but you may have to wait for shipment.



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http://www.uark.edu/ua/isotope/


----- Original Message -----
From: Shelley Kunasek <[log in to unmask]>
Date: Monday, June 26, 2006 6:13 pm
Subject: [ISOGEOCHEM] automate LN2 trap?

> 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]
>