Most countries and states have laws or guidelines for how long you must measure during a home inspection.
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​In the United States and Canada, you have to measure a minimum of 48 hours.
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We recommend measuring at least 48 hours with the Corentium Pro.

Keep in mind that radon levels change and you want to get a good average reading. For the optimal radon level reading, we recommend measuring for 1 month or more. Generally speaking, the longer you measure, the more accurate your readings will be.

We also know that some radon mitigators that give a Home or Wave to their customers as a gift should they have higher levels. This allows homeowners to measure the radon level continuously as radon levels change with the weather and seasons.

A one-time, spot measurement of the radon level is not a good indicator of the radon exposure throughout the year. However, it is much better to do one 48-hour measurement than to never measure at all.