Sampling of solid pollutants and aerosols in imissions

The sampling of imissions for the determination of solid pollutants and aerosols is performed with similar instruments as for the determination of gases. The differences are only in the first two functional parts — in the method of providing the inlet of the air to be analysed and in the way of the absorption or fixation of the component to be determined (see Fig. 5.19). 

The devices for imission sampling for the determination of solid pollutants can be divided into 

The low-volume sampling devices are for aspirating similar amounts of the air analysed as those discussed in Section 5.5.2.1 in connection with sampling procedures for the determination of gaseous pollutants the high-volume ones can handle 20 to 200 cm of air per hour. 

The holders and sampling heads are made of different alloys or plastics. The basic requirements for the holder quality are as follows  

The absorption or fixation of solid pollutants and aerosols is generally accomplished on paper, membrane (nitrocellulose), polystyrene or glass-fibre filters. It should be noted that aerosols may also be sampled directly into absorption solutions (similarly as when sampling gaseous pollutants) and with the help of electrostatic precipitators however, these methods are infrequently used in practice. Particular types of filters are selected depending on the type of the pollutants to be determined. The filter quality is considered from the standpoint of the pore size, efficiency of capture. 

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