Introduction
Diffusive monitoring is widely used in all air monitoring scenarios, i.e. occupational hygiene plus indoor air and ambient air monitoring. By eliminating the requirement for a sampling pump, diffusive monitoring provides a simple and cost method collecting the large number of samples in air monitoring programs.
Key applications include:
- personal exposure monitoring
- large-scale environmental studies
- indoor air monitoring.
Various types of diffusive sampler are available, and the decision on the type of sampler depends on the monitoring scenario.



Radial Diffusive Samplers
Radial ‘Radiello® - type’ diffusive samplers are ideal for short-term diffusive sampling (30 minutes to 6 hours). Typical sampling scenarios include monitoring the effects of industrial processes, changes in traffic volumes or weather patterns. In radial diffusive samplers, the diffusion path is parallel to the radius of the tube. They have a cylindrical diffusive surface area of 23 6 cm2 (over 100× greater than tube-type samplers). This, combined with the short diffusive path, means they have an effective sampling rate typically 100 times that of normal axial tubes.
