How is Radon Measured?

Radon is radioactive, so it is measured using the principles of radiation physics. The way we discover the presence of radon actually involves looking for the radiation given off when radon decays. We have ways to "see" and to "count" the decays of radon.

The unit of measure for radiation is the Curie (Ci), which is a lot of radiation. And we're measuring the levels in air. We actually measure radon levels in picocuries (pCi) per litre of air - pCi/L. What's a curie? 1 Ci = 3.7x1010 decays per second. That's what we mean when we say a curie is a lot of radiation. You don't want to be standing around in a radiation field like this. No way. And by the way, a picocurie is 10-12 Curie.

Pro-Tech uses Sun Nuclear Continuous Radon Monitor's. These monitors are Pa. D.E.P. approved and are the most reliable and popular method for radon testing. These monitors are extremely accurate devices. It records hourly data and has tamper-monitoring features to document any touching, bumping or power interruptions.

In accordance with the Pennsylvania State law, each monitor is calibrated annually, cross-checked against a recently calibrated monitor at six month intervals and every 10th test has two monitors side-by-side to ensure that the results provided are accurate and reliable.

All Radon Test performed by Pro-Tech will include a Certified detailed

test report that indicates the average radon level during the test.

Example of Pro-Tech Report


(Closed House Conditions)

Certain conditions have been established by the EPA that must be followed prior to, and during the Radon Test

Closed house conditions - The house must have all windows and doors kept closed (except for doors can be used for normal entry and exit) during the entire testing period, and for at least 12 hours prior to starting the test. The thermostat for the furnace or A/C should be set to a normal temperature. Everything remains the same except that occupants are not allowed to leave any doors or windows open.

The testing device is placed on the lowest livable area of the home and away from drafts or vents (typically the basement, unless uninhabitable). It should be approximately 20 to 36 inches above the floor and at least 36" away from outside walls, windows or doors.

Pro-Tech's Radon Monitors are left in place for a minimum of 48 hours, and provide fast accurate test results.

Do it Yourself Radon Test Kits

Home test kits are typically not as accurate. But can be exposed from 3 to 7 days (dependent upon manufacturer) and then sent to the laboratory for results. Results may take a week or two. Both methods are excellent as long as the testing conditions are followed.

If you are testing your own home or building, we recommend saving money by using a Do-It-Yourself charcoal test kit, available from many local hardware and home improvement stores and they are easy to use.

If you have any questions after purchasing a test kit from any location, please do not hesitate to call us.