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In response to the appearance of formal regulations, CFR part 1065 subpart J, a new in-use emission measurement system was developed, the OBS 2000. The OBS 2200 uses partial-vacuum analyzers. The heated flame ionization detector (HFID), heated chemiluminescence detector (HCLD) and heated non-dispersive infrared analyzer (HNDIR) are all upstream of the sample pump. This design decreases the response time of the analyzers, lowers power consumption and minimizes the overall dimensions of the system by avoiding the use of a heated sample pump. The size of the heated zones is also minimized to reduce power usage. Typical power consumption of analyzer unit is less than 500 W. The overall dimension of the main unit is 350mm (W) × 330mm (H) × 500mm (D). Analyzer linearity checks as required by new regulations [1] for all available ranges will be presented along with cut point accuracies relative to full scale and percentage of point.

The use of portable emissions measurement systems (PEMS) for testing vehicle emissions while driving on the road has been demonstrated as early as the 1980s. Many users have taken the driving route and repeated the route in a chassis cell with the same vehicle expecting identical results. Emission results can be comparable but there are many factors that need to be considered. This study compares PEMS results for a driving route repeated across seasons and traffic conditions with a single vehicle. The ambient temperature variability and traffic is shown to cause variation in emissions for any individual run. Generating a test cycle to mimic the driving route can be done in a variety of ways. The simplest is to take an individual driving run and translate the time and speed trace directly. This does not address the statistical results from numerous driving runs on the same route.