The Corentium Home is only meant to be used indoors in rooms where you spend most of your time.
We recommend that you always keep the device measuring in areas with below 85% relative humidity. The sensor is an open air sensor which allows air to flow freely into the radon chamber so it is sensitive to the environment it is in - exposure to humidity levels over 85% can cause irreversible damage to the radon sensor.
If you used your device in humid environments and are getting error messages, please follow the guide under this article for troubleshooting:
Corentium Home: can I use it in a high-humidity environment?
Humidity and understand how it effects the Corentium Home.