When you measure changes in atmospheric co2 in the light are you measure net photosynthesis or gross photosynthesis???
When you measure changes in atmospheric co2 in the light you are measuring the gross photosynthesis
This is because the gross photosynthesis is true photosynthesis (carboxylation) while on the other hand, net photosynthesis is true photosynthesis minus photorespiration and dark respiration. Additionally, gross photosynthesis is intended as an integration of apparent photosynthesis which is true photosynthesis minus photorespiration.