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 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 you have finished the test, 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 weeks. If you need results quickly, you should find out how long results will take and, if necessary, request expedited service.

If you hire a qualified radon tester - In many cases, home buyers and sellers may decide to have the radon test done by a qualified radon tester who knows the proper conditions, test devices, and guidelines for obtaining a reliable radon test result. They can also:

• Evaluate the home and recommend a testing approach designed to make sure you get reliable results;
  
  
• Explain how proper conditions can be maintained during the radon test;
  
  
• Emphasize to occupants of a home that a reliable test result depends on their cooperation. Interference with, or disturbance of, the test or closed-house conditions will invalidate the test result;
  
  
• Analyze the data and report measurement results; and
  
  
• Provide an independent test.
  

Your state radon office may also have information about qualified radon testers certification requirements.

Interpreting Radon Test Results
The average indoor radon level is estimated to be about 1.3 pCi/L; roughly 0.4 pCi/L of radon is normally found in the outside air. The U.S. Congress has set a long-term goal that indoor radon levels be no more than outdoor levels. While this goal is not yet technologically achievable for all homes, radon levels in many homes can be reduced to 2 pCi/L or below.