Method for measuring volume of gas [closed]

I would like to setup something up my office to accurately measure the amount of Carbon Dioxide (CO2) being released from beans.

I looked at the site http://examples.yourdictionary.com/examples-of-ways-to-measure-volume.html which suggests several methods, the first of which, fluid displacement, I was going to employ. I know that CO2 is slightly soluble in water so I was going to use a saline solution/brine to reduce solubility. Can anyone help me here in explaining additional things that I should be doing to reduce errors in measurement with this fluid displacement method, other than of course reducing the possibility of air leaks and CO2 solubility? For example I have been reading about the risk of water evaporation in the measuring cylinder so I wonder how this can be minimised? I've also heard about the vander waals methodology for accuracy in calculation.

What other methods should I be considering? I'm not asking for better methods as I realise that's subjective, but other methods that you believe I should be investigating as possible alternatives. I have looked at a gas syringe and a balloon as alternatives.

• Hint: We closed your question as being too broad. It really doesn’t help to make it even broader in an edit … – Jan Sep 24 '17 at 13:50
• @Jan I thought it sounded more refined, clearer, I still do, I'll put that down to inexperience :-( – luke_mclachlan Sep 24 '17 at 17:51

The comment about the van-der-Waals equations: I think that you were probably thinking on using the ideal gas law to estimate the number of gas molecules in a container. $$pV=nRT$$