Skip to content

CO2 Calibration - The Quick method - Desktop Only not mobile

Your sensor calibrates itself

The latest Apollo firmware enables the SCD40's automatic self-calibration by default on every device with the CO2 sensor (AIR-1, R-PRO-1, MSR-2, and MTR-1), so you only need this guide if you turned the CO2 Auto Calibration switch off. See the full calibration guide for how auto calibration works and when to turn it off.

Calibrate manually every 1 to 2 years when auto calibration is off

The SCD40 CO2 sensor has a long lifetime (over 10 years), but with automatic self-calibration turned off it needs re-calibration back to the 420 ppm baseline every 1 to 2 years.

This article will guide you through a simple calibration of your CO2 sensor for any Apollo Automation device!

1. Plug in your sensor outdoors and leave it for at least 5 minutes to allow the readings to stabilize. This should be around 420 ppm per NASA.

2. Go to your Home Assistant dashboard and hit the letter "e" - It will pop up with an entity filter then type in "Calibrate CO2" and select the correct device.

Hint

If you cannot get this menu to pop-up, click somewhere on the Home Assistant dashboard then press your "e" key.

Image of popup with CO2 calibration choice circled in red

3. Click on the button that says "PRESS" and then you are done.

Image of popup with CO2 calibration press button circled in red