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Products shown here are related to the application of thermal desorption for environmental monitoring. Or find out more about environmental applications.

Passive sampling

Passive sampling (diffusive sampling) onto sorbent media uses the principle of Fick’s First law of Diffusion to target known sample environments. Here analytes migrate to the surface of a sorbent bed at a rate dependent on conditions. As no power source is required, the technique can be used for long-term, time-weighted-average monitoring for determining exposure levels in line with occupational health guidance. When used in environmental air monitoring, their relatively

low cost makes them suitable for large-scale deployment.

Axial sampling - Axial diffusive sampling is used for measuring volatile organic compounds (VOCs) in air over a wide concentration range. Depending on the sample concentration axial samplers can be exposed from 8 hours to 4 weeks.

Radial sampling - In radial diffusive samplers, the orientation of the diffusion path is parallel to the radius of the sorbent cartridge. They have a cylindrical diffusive surface area and hence an effective sampling rate typically 100 times that of axial tubes. Due to the higher sampling rate radial samplers are often used for short term deployment (4 hours - 1 week) but are not always suited to sampling high concentration atmospheres.