Sampling of pollutants in emissions

Within the general field of analysis of air pollutants, we will mention only briefly the principles of air sampling for the case of emissions. 

The basic condition for a correct sampling is its isokinetic character. This means that during the analysed air sampling procedure, the gas flow rate through the opening of the sampling apparatus (inlet tubing) should 

The sampling procedure calls first of all for determination of the streaming gas velocity profile. For this purpose, a dynamic velocity probe is used (Prandtl or Pitot tube). This determines the dynamic pressure value at a particular measured point of the given profile. The gas flow rate at the i-the point, u, is directly proportional to the square root of the dynamic pressure at the same point according to the relationship  

4 The separation of aerosol fractions depending on particle sise 

In order to analyse particles of a certain size, which is frequently required, the sample should be divided into fractions immediately foUowing the sampling procedure. 

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