Field Measurements of Particulate Matter Emissions, Carbon Monoxide, and Exhaust Opacity from Heavy-Duty Diesel Vehicles

Abstract

Diesel particulate matter (PM) is a significant contributor to ambient air PM 10 and PM 2.5 particulate levels. In addition, recent literature argues that submicron diesel PM is a pulmonary health hazard. There is difficulty in attributing PM emissions to specific operating modes of a diesel engine, although it is acknowledged that PM production rises dramatically with load and that high PM emissions occur during rapid load increases on turbocharged engines. Snap-acceleration tests generally identify PM associated with rapid transient operating conditions, but not with high load. To quantify the origin of PM during transient engine operation, continuous opacity measurements have been made using a Wager 650CP full flow exhaust opacity meter. Opacity measurements were taken while the vehicles were operated over transient driving cycles on a chassis dynamometer using the West Virginia University (WVU) Transportable Heavy Duty Vehicle Emissions Testing Laboratories. Data were gathered from Detroit Diesel, Cummins, Caterpillar, and Navistar heavy-duty (HD) diesel engines. Driving cycles used were the Central Business District (CBD) cycle, the WVU 5-Peak Truck cycle, the WVU 5-Mile route, and the New IMPLICATIONS Data comparing integrated opacity and integrated PM mass over a transient diesel chassis test cycle have shown a poor correlation between the two measurements. This implies that opacity measurements may not prove to be a precise tool for identifying high PM emitters. Also, in developing models to describe instantaneous mass emissions of PM from a vehicle, it would be unwise to proportion the measured PM mass over the cycle with respect to opacity readings. There is a stronger correlation between CO and PM measurements for the case of a specific vehicle. Therefore, instantaneous CO readings may be used to proportion PM over a cycle to yield an instantaneous PM value. Even though this method may be undesirably inaccurate, it is the only tool presently available to create continuous PM data for inventory modeling using existing databases.

On-Road Particulate Matter (PM2.5 and PM10) Emissions in the Sepulveda Tunnel, Los Angeles, California

“…The 17 runs were carried out over the period July [23][24][25][26][27]1996. The exact times, environmental conditions, and vehicle characteristics observed for each run are given in Table 1.…”

Reanalysis of the DEMS Nested Case‐Control Study of Lung Cancer and Diesel Exhaust: Suitability for Quantitative Risk Assessment

“…(7) However, no information on the extent of DOCs usage in the eight DEMS mines was used in developing any of the REC exposures. Clark et al (27) studied the relationship between particulate matter (PM) and CO in diesel engines operated under different loading conditions, and concluded that that there was no universal relationship between CO and PM, but that that the CO/PM relationship appears to be unique for each engine type and perhaps for each engine. Consequently, the assumption of a fixed quantitative relationship between CO and REC is questionable.…”

On-Road Vehicle Particulate Matter and Gaseous Emission Distributions in Las Vegas, Nevada, Compared with Other Areas

“…Schauer et al 102 Clark et al 106 in 1999 reported dynamometer results for two 1996 D buses. Clark et al 107 showed, in 2003, PM emissions from dynamometer measurements for four HDDVs (average model year 1993.5) by proportioning the The error bars represent the 95% confidence interval for the respective decile mean, calculated using a bootstrap technique.…”