VDI 2468 Blatt 8:2006-03 (R2017)

This guideline specifies a dynamic method for the preparation of PAN calibration gases with concentrations in the range of a few ppb (1 ppb = 10-9), i.e., the relevant range for ambient air measurements. The method is based on the permeation of acetone into a carrier gas flow, followed by photolytic cleavage of the acetone molecules to yield peroxyacetyl radicals and the reaction of these radicals with nitrogen monoxide (NO) to form PAN.