News — pressure

Senseair CO2 Sensor Pressure Dependence

All infrared (NDIR) CO2 sensors have a dependence on pressure. This is because of the physics principle used to measure CO2 concentration. The NDIR type of sensor measures the IR radiation absorbed by CO2 molecules, which corresponds to the mole concentration. When pressure increases, the number of molecules in a given volume also increases linearly. Conversely, when pressure decreases (higher altitudes, for example) the number of molecules decrease. This app note includes both general information about Senseair sensors and pressure, as well as the equation for computing true CO2 level readings at various pressures useful for any NDIR CO2 sensor....

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