Air pollution detection at chimney opening - involves passing air from chimney through foil bag with probe, with size of its outlet opening controlled

摘要

Discharge air flowing from the chimney is passed through an expandable foil bag and inflates it to its fullest extent. A probe is mounted in the foil bag, and its expansion is controlled by varying the size of the outlet opening in accorance with the flow velocity and volume. After the bag has been inflated, its contents may be analysed. The roof (3) supports the measurements appts. (12) which is connected to the chimney and bag assembly by a tube (9).