Field Procedures for Real-World Measurements of Emissions from Diesel Construction Vehicles

Abstract

Construction vehicles are a source of nonroad mobile air pollutant emissions. Emissions from construction vehicles are typically quantified based on steady-state modal engine dynamometer tests using uninstalled stationary engines. However, these tests do not represent real-world activity. Therefore, there is a need to quantify energy use and air pollutant emissions from construction vehicles based on in-use measurement methods. The purpose of this paper is to outline standard procedures for field data collection for construction vehicles. This methodology is based on second-by-second measurement of in-use activity and air pollutant emissions using a portable emissions measurement system. The field data collection methodology includes the development of a study design, installation and use of instrumentation, and field measurements. After the field data collection, the raw data undergo a quality assurance procedure to check for and correct the synchronization between the engine data and emission data. This procedure also identifies missing data and removes incorrect data. The most significant challenges to data collection include suitable weather, difficult operating conditions, and scheduling data collection sessions. Sample real-world data measurement results for a rubber tire loader are presented. The work presented here can be used as a foundational example for conducting other data collection efforts and analysis of construction vehicle emissions.