Isokinetic sampling is to extract the contents of the emission with the same flow rate as the flow of the stack. The initial US EPA Methods 1-4 define the conventions utilised to gather the primary information required to perform isokinetic source testing. This information includes traverse points, stack gas velocity, volumetric flow rate, moisture content, excess air and dry molecular weight of the stack emissions. This data is important for the determination of nozzle size, sampling flow rate and other parameters required to adhere to isokinetic sampling principles.

The equipment used is the ESC 5000 Isokinetic Sampler manufactured in the US.