Home Buyer's and Seller's Guide to Radon is a publication by the Environmental Protection Agency. Used with permission under public domain and creative commons. Usage: Category Education; License: Creative Commons Attribution license (reuse allowed)
On this page: f. Using Testing Devices Properly for Reliable Results
If You Do the Test Yourself - When you are taking a short-term test, close windows and doors to the outside and keep them closed, except for normal entry and exit. If you are taking a short-term test lasting less than four days, be sure to: Close your windows and outside doors at least 12 hours before beginning the test; Do not conduct short-term tests lasting less than four days during severe storms or periods of high winds; Follow the testing instructions and record the start time and date; Place the test device at least 20 inches above the floor in a location where it will not be disturbed and where it will be away from drafts, high heat, high humidity, and exterior walls; Leave the test kit in place for as long as the test instructions say; and Once the test is finished, record the stop time and date, reseal the package, and return it immediately to the lab specified on the package for analysis.
You should receive your test results within a few days or weeks. If you need results quickly, you should find out how long results will take and, if necessary, request expedited service.