Out of curiosity I bought a AIRCO2NTROL MINI CO2 meter from TFA Dostmann [https://www.tfa-dostmann.de/produkt/co2-monitor-airco2ntrol-mini-31-5006/]a few months ago to see just how much a single person (me) increases the CO2 concentration in a room. CO2 concentration is measured in parts per million and a normal