@NurseIngrid2
Have you ensured that it is calibrated?
To check the accuracy of any CO2 meter:
Compare its reading outside compared to the global outdoor CO2 level map:
Click on your location on the map, and you will see current CO2 level outdoors
@NurseIngrid2
aranet is a brilliant bit of kit
had mine since mid 2020. Some of the readings recorded are scary
wouldn’t be without it or a respirator mask