"Gas/gas method" means either of two methods for determining VOM capture efficiency which rely only on gas phase measurements. The first method requires construction of a temporary total enclosure (TTE) to ensure that all would-be fugitive emissions are measured. The second method uses the building or room which houses the coating line, printing line or other emission unit as an enclosure. The second method requires that all other VOM lines or emission units within the room be shut down while the test is performed, but all fans and blowers within the room must be operated according to normal procedures.
Ill. Admin. Code tit. 35, § 211.2550
Added at 17 Ill. Reg. 16504, effective September 27, 1993