When the active concentration of a pollutant is very low a real-time monitor may not be sufficiently sensitive to detect background levels. So, to assess concentrations a large sample must be taken quickly and accurately. In order to verify that there is no impact on the local environment, routine air sampling for such pollutants is often undertaken.

The large volume samplers will draw against a restriction of 250mbar or more so that samples of hundreds of cubic metres can be taken using a variety of media.

Sampling of radioactive particles in the nuclear industries is the most common application as well as in pharmaceutical production and environmental monitoring where the lowest detection limits are required.