Heavy Duty Vehicle / Diesel Fleet Monitoring & Testing

Light duty gasoline vehicles have made many great technological advances, leaving diesel engines responsible for a growing fraction of mobile source nitrogen oxides (NOX) and particulate matter (OM) emissions.  For example, in California heavy-duty diesel vehicles (HDDV) represent only 2 percent of the vehicle fleet but contribute about 30 percent of the nitrogen oxides and 65 percent of the particulate emissions from motor vehicles.[1]

Opus Inspection RSDs have accurately measured the NOx and PM emitted by heavy duty diesel vehicles for decades.  With Opus remote sensing, there is no need to take these vehicles out of service to obtain accurate emissions records.  This makes RSD a cost effective way to monitor, identify, and diagnosis of emissions-related problems with heavy-duty vehicles.


Because it is expensive and impractical to inspect heavy-duty vehicle (HDV) emissions on a dynamometer within brick and mortar stations, Opus Inspection offers the On-Road Heavy Duty Measurement System (OHMS), a remote emissions sampling technique originally developed at the University of Denver.  HDVs simply pass through the 100 foot long, peaked-roof tent pictured here as a perforated tube at the apex continuously samples the exhaust.  The system channels that exhaust to an assembly of traditional gaseous and specialized particulate analyzers.   Passing through the OHMS takes seconds.  If the process is combined with a quick pre-OHMS stop to present registration and a post-OHMS stop to collect payment and present inspection results, the OHMS can serve as an inexpensive and practical substitute for a brick-and mortar inspection stations.

If combined with on-road remote sensing screening to extend the OHMS inspection date for the lowest-emitting vehicles and shorten the OHMS inspection date for the highest-emitting vehicles, jurisdictions can achieve the most efficient approach to HDV emissions inspection.   The North Central Texas Council of Governments, in partnership with Texas A&M University and Opus Inspection are pilot-testing this combined approach to HDV emissions inspection.

[1] California Air Resources Board, 2004 (http://www.arb.ca.gov/msprog/hdvip/hdvip.htm see pampl1-4.pdf)