Environmental Diffusive Air Sampling

Axial and radial diffusive sampling

Diffusive sampling provides a low cost and non-intrusive alternative to pumped tube sampling for many routine industrial hygiene and ambient air monitoring applications.  Relevant standard methods include ISO 16017-2, ASTM D6196-03, prEN 14662-4 and UK MDHS 80. 

Well-validated uptake rates for Markes-type axial diffusive tubes are published in these standards and include an extensive list of common solvents.  This information is summarised in Markes TD Technical Support Note #1. Markes International also provides unique SafeLok™ tubes for simple generation and validation of axial uptake rates. 

Relevant technical support publications from Markes International can be automatically downloaded from this web site (registration required). Examples include:

• TDTS 1 - Uptake rates on axial diffusive samplers
• TDTS 2 - Prediction of uptake rates for diffusive tubes
• TDTS 10 - Use of diffusive samplers with thermal desorption - capillary GC analysis for monitoring VOCs in ambient air 
• TDTS 18 - Development in the determination of nitrous oxide exposure using thermal desorption-GC 
• TDTS 25 - Calculating atmospheric concentrations from analyte masses retained on sorbent tubes
• TDTS 42 - Uptake rates for radial diffusive samplers