About

• Active sampling: Unlike passive methods, air samplers force a measured volume of air through a collection medium.
• Particle collection:
  • Microbial samplers: Draw air through or onto a culture medium (like an agar plate) to capture and grow airborne microorganisms for analysis, say TM Media.
  • Particulate samplers: Pull air through a pre-weighed filter. After a set period, the filter is re-weighed to determine the mass of collected particles, according to the Queensland Government.
• Analysis: After sampling, the collection medium is analyzed. This can involve:
  • Incubating agar plates to count colonies of microorganisms.
  • Weighing filters to calculate the concentration of suspended particles, notes the Queensland Government.
  • Using chromatography or spectroscopy on the collected sample for chemical analysis. 

• High and low volume samplers: Differ in the amount of air they process. High volume samplers are used for total suspended particulate (TSP) monitoring, drawing large volumes of air over 24 hours.
• Microbial samplers: Specifically designed for detecting microorganisms and include various technologies:
  • Impaction: Air is forced through small holes to impact particles onto an agar surface.
  • Centrifugal: Use centrifugal force to collect microbes onto the medium.
  • Filtration: Pass air through a sterile filter, which is then placed on a growth medium.
  • Liquid Impingers: Capture microbes in a liquid medium.
• Particle counters: Laser-based devices that directly measure the concentration of particles of specific sizes in the air.
• Spore traps: Use an adhesive surface to continuously trap particles, allowing for analysis over a longer period. 

• Pharmaceuticals: Monitoring cleanrooms to ensure sterility and prevent product contamination.
• Industrial hygiene: Measuring worker exposure to hazardous substances like dust, gases, and vapors in the workplace.
• Environmental monitoring: Assessing air pollution in urban areas and monitoring air quality after natural or industrial disasters.
• Indoor air quality: Monitoring the air in public spaces like airports and schools for public health.