Part 2: Testing the Release of Carbon Dioxide
After the carbon dioxide meters have been calibrated, two tests must be done since the carbon dioxide can be released in two ways into the atmosphere: escape directly as carbon dioxide through the hole on the plant's side of the device; convert into oxygen through photosynthesis and get released into the atmosphere through the hole on the plant's side of the device.
The tests will help gather data in either situation of how much carbon dioxide is returning to the atmosphere and how much is getting converted into oxygen.
EXPERIMENT #2
The second way in which the carbon dioxide can escape into the atmosphere is by being converted into oxygen and then being released through the hole in the plant compartment of the filtering system. To test how much oxygen is being made, a closed container with the potted English Ivy and a carbon dioxide meter will be exposed to pure carbon dioxide from the carbon dioxide tank. The closed container would not allow for the escape of carbon dioxide so the only way that the carbon dioxide levels would drop is if the carbon dioxide is being converted into oxygen through photosynthesis by the plants. Over a duration of time (ten minutes), the carbon dioxide levels can be monitored. The data will indicate the change in the carbon dioxide levels and the production of oxygen, which can be used to calculate the rate of conversion and the efficiency of the carbon dioxide-to-oxygen conversion.
Below is a video demonstrating the second experiment in part two of finding the conversion efficiency.
This data indicates that the average air exchange for the system is decreasing. Sensor 1 has an air exchange rate of -0.7146 ppm CO2/hour and Sensor 2 has a value of -0.73107 ppm CO2/hour. This shows that the amount of carbon dioxide is decreasing over time in a closed system, as expected, because some of the carbon dioxide released is converted into something else (possibly oxygen).
