> ## Documentation Index
> Fetch the complete documentation index at: https://waybeyond.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# How to calibrate the Folium CO₂ sensor
> To keep CO₂ readings accurate, calibrate the Folium CO₂ sensor outdoors every 6 months using these instructions below.
| **Step** | **Calibration** | **Notes** |
| :------- | :--------------------------------------------------------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| 1 | Take the **Folium sensor**(s) outside and wait **5** minutes for the sensor(s) to stabilise. | **Note:** The time is to allow for the sensor to start accurately reading it's new environment. **Avoid** breathing towards the unit for these steps as the additional CO₂ contained in exhaled human breath can cause the calibration to be incorrect. |
| 2 | Press and hold the Power Button on the bottom of the **Folium sensor** for approx. 30 seconds until the unit lights up **orange**. | **Note:** If the button is only pressed or is released early the unit will flash green and the user will have to wait until the flashing stops to restart the calibration. |
| 3 | When the **orange** flashing finishes with a **green** flash the calibration is complete. | **Note:** the calibration technique assumes atmospheric CO₂ is 400ppm and that the sensors CO₂ sensor is reading atmospheric conditions. |
| 4 | Repeat calibration every 6 months. | \*\* \*\* |
If you accidently release the power button during the calibration period, the lights will light up green. Please wait for this to stop and then try again.