Real Drive Emission Measurement on CEV Machinery- Study of testing challenges and different machine duty cycles.

India is witnessing a rise in CEV sales concurrent with the increase in large-scale infrastructure projects. This will lead to greater contribution to ambient air pollution from this category of vehicles. India has made huge strides in harmonizing the emission regulations with the rest of the world and has mandated RDE tests on Tractor and CEV machines under AIS 137 Part 7-A2 CEV/TREM Stage V emission norms starting from April 1, 2026. To conduct RDE test on CEV, the first step is to study the requirements set forth in the regulation for data collection, post-processing of data and emission calculation along with certain requirements for vehicle operation. Conducting tests on CEV machines poses a different set of challenges compared to on-road vehicles, the major one being the placement of PEMS (Portable Emission Measurement Equipment) on the machine under test. No singular method or mechanism can be specified to suit all types of machinery, although certain guidelines can be set for best practices. The requirement of running the machine on an actual duty cycle or a reference duty cycle requires a thorough study of the intended machine operation and also awareness on the multi-functionality setups offered for such machines by manufacturers, before deciding on a duty cycle to run during actual emission testing. Measurement of emission components such as Carbon Monoxide (CO), Total Hydrocarbons (THC), Nitrogen Oxides (NOx) and Carbon Dioxide (CO2) is required along with Exhaust flow and ECU parameters like Engine speed, Torque (Actual, Friction, Reference), fuel flow and coolant temperature is required for conducting a valid test. Exploring the impact on emission results of different machine applications, machine duty cycles, environmental and geographical conditions is also of utmost importance to ensure robust engine calibration which will meet future conformity limits. Tests on same CEV machinery within same geographical and ambient conditions but under different duty cycle have shown variation in emission results, this study will delve deeper into this impact of duty cycle on emission results.