About Emissions Testing

Emissions testing consists of collecting and characterizing the exhaust of an engine while also controlling (or at least measuring) the engine's activity. All exhaust contains gas, which results from the chemical reactions between the intake air and the fuel in engine cylinder. Exhaust may also contain particulate matter: tiny grains of complex carbon compounds, which, in high concentrations, are visible as grey or black smoke.

There are many reasons to perform emissions testing but the most important three are:

• An organization may need to prove compliance with a regulatory authority, such as the EPA. This certification may be required in order to sell a product, such as a fuel additive, engine, vehicle or aftermarket device.
• An organization may wish to demonstrate the degree of environmental impact of their own process or another organization's process. Additionally they may want to determine the most cost effective way to lessen it, such as by comparing hybrid electric or aftertreatment technology to conventional vehicles or engines.
• An organization may wish to develop a new engine-related product or refine an existing one, and without emissions testing they can't determine if they are making progress.

If the results of the emissions test must be submitted to a regulatory authority, then the test must be run according to their regulations. This usually restricts the methodology and equipment that can be used and requires the process to the more thoroughly documented. In other cases newer technologies can be used, which provide more detailed information but sometimes sacrificing accuracy.