In the near future, opacity testing – commonly referred to as the sniff test – will become more commonplace to detect emissions cheaters.
In an effort to control excessive smoke emissions, California already requires annual smoke inspections for heavy duty vehicles, notes Taylor of FSX Equipment. This is through the California Air Resource Board’s Periodic Smoke Inspection Program (PSIP).
The PSIP requires diesel and bus fleet owners to conduct annual smoke opacity inspections of their vehicles, and repair those with excessive smoke emissions to ensure compliance.
A fleet owner that neglects to perform the annual smoke opacity inspection is subject to a penalty of $500 per vehicle, per year. The penalties for excessive smoke range from a fix-it ticket to a $1,800 citation, and the California Highway Patrol can take the vehicle out of service.
Basically, a smoke test is a simple, brief test performed on a vehicle when it is standing still and in neutral. The engine is accelerated while a smoke meter is placed at the end of the exhaust pipe and the opacity of the smoke is measured.
The opacity, expressed as a percentage of light reduction, is the degree to which the exhaust obscures a beam of light shining through it.
A number of other states have laws that require heavy duty vehicles to submit to random roadside diesel opacity testing when requested by the appropriate authority. It is anticipated that the U.S. EPA will soon consider legislation aimed at increasing such programs.