Emission test cycle

An emission test cycle, also known as a 'smog check', is a specified procedure for measuring pollutant

Pollutant

A pollutant is a waste material that pollutes air, water or soil, and is the cause of pollution.Three factors determine the severity of a pollutant: its chemical nature, its concentration and its persistence. Some pollutants are biodegradable and therefore will not persist in the environment in the...

 emissions of engines. For emission measurements to be comparable for different engines in a category, the measurements are performed under a specific operating pattern, or 'test cycle' of alternating high, medium, and low engine load. The test cycle should ideally reflect a 'normal' usage pattern concerning speed and acceleration. Realistic test cycles are instrumental for the environmental integrity of emission standards. It was recently discovered that engine manufacturers would engage in 'cycle beating' to optimize emission performance to the test cycle against which European vehicle emission standards

European emission standards

European emission standards define the acceptable limits for exhaust emissions of new vehicles sold in EU member states. The emission standards are defined in a series of European Union directives staging the progressive introduction of increasingly stringent standards.Currently, emissions of...

 were tested, with the result that real-life emissions would be much higher than expected, undermining the standards and public health.

Application

Emission test cycles are typical tests for research and development activities on engines at automobile OEMs.

The commonly used hardware platforms therefore are:

• engine test stand
  Engine test stand
  An engine test stand is a facility used to develop, characterize and test engines. The facility, often offered as a product to automotive OEMs, allows engine operation in different operating regimes and offers measurement of several physical variables associated with the engine operation.A...
  
   - for just a single engine
• vehicle test stand (also "chassis dynamometer" or "chassis dyno" or "emission dyno") - for the complete car with engine
• ASM Test - Accelerated Simulation Mode: (California inspections) Vehicles tested at 15 MPH & 25 MPH where vehicle undergoes a load.

External links

• Dieselnet overview of commonly used test cycles
• Cycle beating and the EU test cycle for Cars. European Federation for Transport and Environment
  European Federation for Transport and Environment
  The European Federation for Transport and Environment is a European umbrella for non-governmental organisations working in the field of transport and the environment, promoting sustainable transport in Europe; which means an approach to transport that is environmentally responsible, economically...
  
  , November 1998
• Poor European test standards understate air pollution from cars European Environment Agency
  European Environment Agency
  European Environment Agency is an agency of the European Union. Its task is to provide sound, independent information on the environment. It is a major information source for those involved in developing, adopting, implementing and evaluating environmental policy, and also the general public...
  
  news release. Copenhagen/Amsterdam, 19 October 2004.