This part of ISO 11042 establishes the methods used for the measurement and evaluation of the emission of the exhaust gases from gas turbines and defines appropriate emission terms. It presents requirements for the test environment and instrumentation as well as the quality of measurement and correction of data. This allows uniform judgement of the exhaust emissions. The relationship between the various forms of expressing the exhaust emissions is also given.

The constituents to be measured in accordance with this part of ISO 11042 standard should be determined by mutual agreement between the parties involved.

This part of ISO 11042 is applicable for all gas turbines producing mechanical shaft power and/or which are used as drivers for electrical generation excluding application in aircraft. For installations which include an exhaust gas heat recuperation system, the definitions of this part of ISO 11042 can be used as a basis.

This part of ISO 11042 is applicable for gas turbines which utilize the open cycle process. It is also applicable as a basis for gas turbines which utilize the semi-closed cycle and gas turbines equipped with free piston compressors or with special heat sources.

This part of ISO 11042 can be used as an acceptance test for gas turbine exhaust gas emissions.