Portable emissions measurement system

A portable emissions measurement system (PEMS) is a vehicle emissions testing device that is small and light enough to be carried inside or moved with a motor vehicle that is being driven during testing, rather than on the stationary rollers of a dynamometer that only simulates real-world driving. A portable emissions measurement system (PEMS) is a vehicle emissions testing device that is small and light enough to be carried inside or moved with a motor vehicle that is being driven during testing, rather than on the stationary rollers of a dynamometer that only simulates real-world driving. Early examples of mobile vehicle emissions equipment were developed and marketed in the early 1990s by Warren Spring Laboratory UK during the early 1990s, which was used to measure on-road emissions as part of the UK Environment Research Program. Governmental agencies like United States Environmental Protection Agency (USEPA), European Union,, and various states and private entities have begun to use PEMS in order to reduce both the costs and time involved in making mobile emissions decisions. Leo Breton of the US EPA invented the Real-time On-road Vehicle Emissions Reporter (ROVER) in 1995. The first commercially available device was invented by Michal Vojtisek-Lom, and developed by David Miller of Clean Air Technologies International (CATI) Inc. in Buffalo, New York in 1999. These early field devices used engine data from either an on-board diagnostics (OBD) port, or directly from an engine sensor array. The first unit was developed for, and sold to - Dr. H. Christopher Frey of North Carolina State University (NCSU) for the first on-road testing project, which was sponsored by the North Carolina Department of Transportation. David W. Miller, who co-founded CATI, first coined the phrase 'Portable Emissions Measurement System' and 'PEMS' when working on a 2000 New York City Metropolitan Transportation Agency bus project with Dr. Thomas Lanni of the New York State Department of Environmental Conservation, as a short-hand description of the new device. Other governmental groups and universities soon followed, and quickly began to use the equipment due to its balance of accuracy, low cost, light weight, and availability. From 1999 through 2004, research groups such as Virginia Tech, Penn State, and Texas A&M Transportation Institute, Texas Southern University and others began to use PEMS in border crossing projects, roadway evaluations, traffic control methods, before-and-after scenarios, and ferries, planes, and off-road vehicles, to explore what was possible outside of a lab environment. A project performed in April 2002 by the California Air Resources Board(CARB) - using non-1065 PEMS equipment, tested 40 trucks over a period of 2½ days; of which, 22 trucks were tested on road in Tulare, California. During this time, a high-profile project performed with early PEMS equipment was the World Trade Center (WTC) Ground Zero Project in lower Manhattan, testing concrete pumpers, bulldozers, graders, and later - diesel cranes on Building #7 - 40 stories high. Other early PEMS projects such as Dr. Chris Frey's field work was used by the USEPA in the development of the MOVES Model. However, users such as regulators and vehicle manufacturers had to wait for ROVER to be commercialized to conduct actual measurements of mass emissions rather than depend on estimates of mass emissions using data the OBD port, or a direct engine measurement, in order to have a more defensible data set. This push led to a new 2005 standard known as CFR 40 Part 1065. Many governmental entities (such as the USEPA and the United Nations Framework Convention on Climate Change or UNFCCC) have identified target mobile-source pollutants in various mobile standards as CO2, NOx, Particulate Matter (PM), Carbon Monoxide (CO), Hydrocarbons(HC), to ensure that emissions standards are being met. Further, these governing bodies have begun adopting in-use testing program for non-road diesel engines, as well as other types of internal combustion engines, and are requiring the use of PEMS testing. It is important to delineate the various classifications of the latest 'transferable' emissions testing equipment from-time PEMS equipment, in order to best understand the desire of portability in field-testing of emissions. Because a PEMS unit is able to be carried easily by one person from jobsite to jobsite, and can be used without the requirement of 'team lifting', the required emissions testing projects are economically viable. Simply put, more testing can be done more quickly, by less workers, dramatically increasing the amount of testing done in a certain time period. This in turn, significantly reduces the 'cost per test', yet at the same time increases the overall accuracy required in a 'real-world' environment. Because the law of large numbers will create a convergence of results, it means that repeatability, predictability, and accuracy are enhanced, while simultaneously reducing the overall cost of the testing.