Review on GZAIR Temperature Relative Mountable: Advanced 0-5000ppm Sensing for Precise Monitoring by Ryan Bennett

I live in a van and am often concerned about carbon dioxide levels in such a small enclosed space. I always open the windows and air the room when I feel like I'm noticing a small amount of oxygen, but that's all subjective, to the point where I feel like I've developed a bit of paranoia, which I'm doing right now did need an actual way to know the CO2 concentration. So I bought it for this purpose. I wanted to make sure I tested this device thoroughly before leaving a review. Here are my thoughts: Works very well when placed correctly. I would like to point out that if you have this item in close proximity to a person in an enclosed space, the readings will be everywhere. Reviews that say the readings are unstable don't seem to have a good understanding of the physics involved, they just want to place the meter in the most convenient spot, like a bedside table, where it won't be as useful. Exhaling carbon dioxide near a carbon dioxide meter simply fills that meter with carbon dioxide and prevents it from getting an accurate reading of the total carbon dioxide concentration throughout the room. You should place it as far away as possible from areas you will be in or areas that will be affected by air displacement when entering rooms, closing doors, etc. The 'least disturbed areas' that you to be able to imagine. This allows the exhaled carbon dioxide to mix with and circulate in the room air for an accurate concentration reading. Very happy with this machine once you understand what you are doing. what you do and how you can artificially affect the readings, I think you will like this machine too. I absolutely recommend this to anyone concerned about CO2 in their space.