BAM stands for Beta Attenuation Monitor, the BAM-1020 automatically measures and records airborne particulate concentration levels (in milligrams or micrograms per cubic meter) using the industry-proven principle of beta ray attenuation.Thousands of BAM-1020 units are currently deployed worldwide, making the unit one of the most successful air monitoring platforms in the world.

The Met One Instruments Model BAM-1020 was the first instrument to obtain U.S. EPA Federal Equivalent Method (FEM) designation for continuous PM2.5 monitoring, in addition to its longstanding EPA designation for PM10 monitoring. The BAM-1020 has also obtained the corresponding PM2.5 and PM10 certifications in the European Union. Two BAM-1020 units can also be operated together as an EPA designated PM10-2.5 coarse method. Met One Instruments supplies complete sampling accessory kits for compliance with each designation.

Operating Principle

Measures ambient particulate concentrations using beta ray attenuation

U.S. EPA Designations

Class III FEM,

PM10 (EQPM-0798-122)

PM2.5 (EQPM-0308-170)

PM10-2.5 (EQPM-0709-185)


EU Certifications

TUV Rheinland,

PM2.5 (936/21209919/A)

PM10 (936/21205333/A, 936/21220762/A)


Data Collection

All data files are accessible via an industry standard two-way RS-232 serial port using common terminal programs or Met One Instruments software such as Air Plus™ and 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. Optional Ethernet and USB data collection support is also available.

Error Handling

The BAM-1020 performs continuous user selected evaluation of a variety of criteria for data validation including flow statistics and a comprehensive set of error codes including power failures, flow failures, hardware failures, tape errors, nozzle errors, span check errors, beta count errors, and more.



The BAM-1020 is designed to run continuously with only monthly or bi-monthly scheduled maintenance a single roll of filter tape will last more than 60 days. The BAM-1020 also contains a comprehensive self-test function which allows the unit to preemptively test itself for any mechanical failures in the tape control system




  • Operation Manual and Quick Setup Guide

  • Internal Automatic Span Membrane

  • Internal Flow Sensor and Flow Controller

  • Internal Filter Temperature, Pressure, and RH Sensors

  • Six Channel Data Logger for Accessory Sensors

  • Serial Data Cable and Modular Power Cable

  • Pump Control Cable and Air Tubing

  • Rack Mounting Brackets and Hardware

  • Comet™ Data Collection Software

  • One Roll of 460130 Glass Fiber Filter Tape