Radon and radon decay product concentrations in a building fluctuate from hour to hour, from day to day and from season to season. The following test conditions have been developed to provide standardised test conditions under which a short term radon survey is to be performed in order to reduce the variation in radon levels in a building (American Environmental Protection Agency guidelines.) These conditions will tend to maximise the radon measurement to determine if the building has the ‘potential’ to have an elevated radon level. If the results are high, further testing is recommended to better determine the yearly average concentration.

A print out of the test results for each hour of the test on thermal paper direct from the RAD7 printer.

A graphical representation on A4 paper of the radon levels downloaded from the RAD7 over the test period together with concurrent data from a weather station at Gunnislake. This includes a barometric record.

Note: Barometric pressures are likely to be relevant over a large area, up to 100 miles from the weather station.

If the test conditions as described below are not adhered to, the test may be deemed invalid. These conditions must be read and understood by the ‘responsible person’ for, and complied with by the occupants of, the building.

All windows must be kept closed. All doors giving access to outside must be kept closed except for normal, momentary, entering and exiting.

Radon detectors are not to be moved, covered or altered in any way. Heating, air conditioners, clothes dryers, cooker hoods and bathroom fans can be operated normally. If any heating, air conditioning or ventilation equipment has a built in outdoor air supply that is manually controlled, it shall be turned off or the inlet closed. Fireplaces or wood stoves are not to be operated unless they are a primary heat source.

These test conditions are to be maintained 12 hours prior to the start of the test, unless the test is longer than four days duration.

Any installed radon mitigation systems are to be operated normally.

The dates of the commencement and completion of the test.

A statement as to whether the ‘responsible person’ for the building signed a ‘declaration of understanding and compliance’ with the required test conditions.

The general climatic conditions during the test period.

Whether the required doors and windows were closed at the beginning and end of the test together with a general observation as to whether the test conditions appeared to have been maintained.

A general comment on the property.

The actual maximum, minimum and average radon values recorded during the test period.

Test conclusions.

If there are any questions, or the test conditions are not met, please contact The Cornwall Radon Gas Centre on 01822 832816.