A piece of tissue paper is placed on a screen mesh over the input port of a vacuum cleaner. After the air is sucked through the vacuum cleaner for about 15 minutes (depending on how much radon gas is present) the tissue is placed by the window of a Geiger tube. The increased count rate is clearly evident, showing that radioactive materials are on the tissue. This count rate can be contrasted with the count rate of a clean piece of the same tissue paper.
The radioactivity results from radioactive daughters of radon gas which are solids and attach themselves to dust particles in the air. The tissue removes these dust particles as the air is sucked through the vacuum cleaner.
Also included are a home-type radon testing kit along with copies of the descriptive literature.