The use of Palmes diffusion tubes for measuring NO2 in homes.

The results of exposure chamber and field validation tests of NO2 diffusion tubes are reported. In an exposure chamber about 50 test runs at various relative humidities were performed. The field validation consisted of comparisons between tubes and a chemiluminescence monitor in 9 homes during several days in kitchen, living room, bedroom and outdoors. The results indicate a dependency on relative humidity, while the often quoted accuracy of 10% for the diffusion tubes might be too optimistic for the use of the tubes in homes.