It has been known that variations in ambient temperature, pressure, and humidity can have significant effects on measured emissions levels. Although the need to account for variation in ambient conditions is generally recognized, and several studies have attempted to establish more or less universal correction factors, there is no widely accepted procedure for the correction of emissions measurements to reference-day ambient conditions. A current program by the EPA is to establish a wide data base from which procedures for correction of measured emissions levels to reference day conditions can be developed. To establish this data base, EPA contracted with three engine manufacturers to make tests under controlled ambient conditions. To supplement these data, industry and other government agencies were requested to submit data that could be used in establishing an acceptable correction procedure. The CFM 56 engine was selected for this study because it is representative of the next engine of highly efficient, large turbofans which will be in production when EPA gaseous emissions standards first become effective in the early 1980's.

"EPA-460/3-79-011." "December 1979." "R79AEG632"--T.p. "Contract No. 68-03-2388"--T.p. "EPA Project Officer: Richard W. Munt"--T.p. Includes bibliographical references (p. 117).