BAM 1020 Beta Attenuation Mass Monitor MET ONE INSTRUMENTS

The BAM 1020 from Met One Instruments Powered by Acoem was the first instrument to obtain U.S. EPA Federal Equivalent Method (FEM) designation for continuous PM_2.5 monitoring, in addition to its longstanding EPA designation for PM₁₀ monitoring. The BAM 1020 has also obtained the corresponding PM_2.5 and PM₁₀ certifications in the European Union. Two BAM 1020 units can also be operated together as an EPA designated PM_10–2.5 coarse method. Met One Instruments Powered by Acoem supplies complete sampling accessory kits for compliance with each designation.

At the beginning of each sample hour, a small ¹⁴C (carbon-14) source emits a constant source of high-energy electrons (known as beta rays) through a spot of clean filter tape. These beta rays are detected and counted by a sensitive scintillation detector to determine a zero reading. The BAM 1020 then advances this spot of tape to the sample nozzle, where a vacuum pump pulls a measured and controlled amount of outside air through the filter tape, loading it with ambient dust. At the end of the sample hour, this dust spot is placed back between the beta source and the detector, thereby causing attenuation of the beta ray signal which is used to determine the mass of the particulate matter on the filter tape. This mass is used to calculate the volumetric concentration of particulate matter in the sampled ambient air.

All data files are accessible via an industry standard duplex RS-232 serial port using common terminal programs or Met One Instruments’ software such as Air Plus® or Comet®. The data is available in a variety of formats including daily reports, last record, all data, and new records since last download. Configuration files, error logs, and flow statistics are also available. Ethernet and USB data collection are standard.