Gas Turbine Engine Emissions Measurement Technology: An Overview

Current technology and practices at Pratt & Whitney Aircraft Group, Commercial Products Division (P& WA) for monitoring gas turbine engine emissions as a function of engine operating parameters, fuels, and environmental factors are discussed from sampling procedures through final data reduction. Mobile laboratories and fixed systems are used to rapidly measure smoke, hydrocarbons, oxygen, oxides of nitrogen, water, carbon monoxide and carbon dioxide content. Calibration gases, traceable to the National Bureau of Standards (NBS), are provided by an in-house calibration laboratory. The data collected are fed into a computer to calculate emission factors, concentration levels, and when requested, gas temperature from the measured emissions. Problem areas, including an overall assessment of measurement accuracy, are discussed.