Hi all, i have been assigned to study indoor air quality and car cabin air quality project. My Problem is: How to measure Carbon Dioxide concentration in that constant volume of air? (consider there will be changes in the concentration and i need to quantify or contrast it at least.) Yes i know there are multiple gas sensors out in the market, but those are quite beyond the allocation available for this project. i have heard of but have not tried using chemical solution such as (liquid calcium carbonate) actually can measure the differences of the CO2 concentration? Thanks in advance.