title: Modified double filter method for the measurement of radon or thoron in air.
mesh_terms: D000388:Air / Q000032:analysis*; D005374:Filtration / Q000379:methods; D011868:Radioisotopes / Q000032:analysis; D011886:Radon / Q000032:analysis*
chemical_list: D011868:Radioisotopes; D011886:Radon