The diffusive samplers uses very simple tools that can exploit a natural law (that of molecular diffusion) to enrich on a substrate adsorbing substances in the air as gases or vapors. The amount of pollutant sampled may be determined by an appropriate quantitative analysis. Its average concentration is determined by knowing: the duration of sampling, the equivalent range and mass (measured analytically) of the pollutant in question.
The RING is a radial symmetry diffusive sampler  characterized by  a cylindrical diffusive surface (rather than flat), an adsorbent device also cylindrical, internal and coaxial to the surface diffusive,  and a diffusive path parallel to the beam.  A radial symmetry sampling allows, with the same accuracy and precision, a capture speed much greater than that obtained with the axial symmetry and thus a higher sensitivity. Its high sensitivity makes it possible to obtain accurate results with exposures of a few hours or a few weeks. The RING  is ideal for both environmental and personal monitoring.