Met One Instruments, Inc. BAM 1022, Real-Time Portable Beta Attenuation Mass Monitor, continuously measures the mass concentration of ambient particulate matter collected onto glass filter tape with time resolution of one-minute. The BAM 1022 employs an in-line sampling geometry in which the attenuation of beta rays across filter media is measured and particulate matter is sampled simultaneously. This allows ambient sampling to occur for virtually 60 minutes each hour. It also allows for beta ray measurements to be made for virtually the entire hour thereby improving sensitivity and time resolution. 


The BAM 1022 employs a unique “in-situ” sampling technique where the beta measurement is kept at a near fixed temperature above ambient conditions, thereby minimizing measurement error due to loss of semivolatile particulate material or due to excessive moisture in the sample stream. Highly accurate measurements are made without having to employ expensive Nafion dryers thereby increasing reliability and decreasing operating costs. The integrated shelter does not employ air conditioning, nor does the sampling system employ flow splitters. This results in easier service, enhanced reliability

and lower power consumption.

The BAM 1022 comes integrated into its own lightweight enclosure with easily detachable pump box making it ideal for installation in areas where no permanent structure or walk-in shelter is available. Power consumption is modest as no air conditioning is required. No component weighs more than 40 lb. (18K) meaning that it is easily transportable by one person. The entire system may be set up and put into operation in less than ten minutes.

Operating Principle

Measures ambient particulate concentrations using beta ray attenuation

U.S. EPA Designations

Class III FEM,

PM2.5 (EQPM-1013-209)








Advanced Features

  • In-Situ measurement of PM that provides high accuracy, minimal measurement artifacts.

  • Reduced background determination frequency.

  • Unsurpassed performance under high ambient dew point operation.

  • Advanced communications features allowing remote operation and

    cloud-based communication.

  • Advanced diagnostics.

  • Improved sensitivity compared to other in-line beta attenuation mass monitors.

  • Meteorological and other sensor inputs.