The particulates monitor is a BAM (beta attenuation monitor). Every hour, the tape advances and a radioactive source (Carbon 14) emits electrons that pass through the paper to a receptor. The tape then backs to expose the paper filter to airflow where, for 50 minutes, it collects particles carried in the air. That section of the paper tape then returns to the radiation source, where the accumulated particles attenuate the amount of electrons passing through to the receptor. The difference between the before and after exposure provide a measurement of amount of PM2.5 in the air. The PM2.5 concentration is reported as micrograms per cubic meter of air. Every two months the tape is changed by staff of the Sable Island Station.