Re: VRD - Testing Carbon dioxide in air

I do not know of a substance that will measure CO2 depletion:  there will 
still be some CO2 there, if I understand your project correctly.

There are a couple of ways to measure the gas concentration.  Neither of 
them are cheap.  What I would recommend is calling a local industrial 
hygiene consulting company in your area.  They can help and possibly even 
donate time/equipment!  You can find one by going to the web site:  
www.aiha.org and looking at the consultants listing.

The two methods are as follows:

(1) drawing air into a sampling tube.  This has an accuracy of +/- 20%.  
These sampling tubes are made by the Draeger Company or the Sensodyne 
Company.

(2) Using a direct reading instrument that measures CO2 and other gasses.  
These instruments can be rented from a company called HAZCO (1-800-332-
0435).  They may even be able to help with the cost, since this is a 
school project.

Good Luck!