This standard collects radioactive particulate matter (hereinafter referred to as radioactive dust) suspended in the air using a filtration type dust sampler in the facility's working environment, surrounding environment, facility exhaust system, etc., and performs Geiger-Mueller counting. When alpha, beta, or gamma rays are detected by a tube, scintillation detector, etc., and the indicated value is higher than the radioactivity level set for radiation control, for the purpose of radiation protection, Specifies radioactive dust monitors (hereinafter referred to as dust monitors) that issue alarms.