An emission test cycle is a protocol contained in an

emission standard Emission standards are the legal requirements governing air pollutants released into the atmosphere. Emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from specific sources over ...

to allow repeatable and comparable measurement of exhaust emissions for different engines or vehicles. Test cycles specify the specific conditions under which the engine or vehicle is operated during the emission test. There are many different test cycles issued by various national and international governments and working groups. Specified parameters in a test cycle include a range of

operating temperature An operating temperature is the allowable temperature range of the local ambient environment at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the de ...

, speed, and load. Ideally these are specified so as to accurately and realistically represent the range of conditions under which the vehicle or engine will be operated in actual use. Because it is impractical to test an engine or vehicle under every possible combination of speed, load, and temperature, this may not actually be the case. Vehicle and engine manufacturers may exploit the limited number of test conditions in the cycle by programming their engine management systems to control emissions to regulated levels at the specific test points contained in the cycle, but create a great deal more pollution under conditions experienced in real operation but not represented in the test cycle. This results in real emissions higher than the standards are supposed to allow, 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 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 varia ...

- 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.

Application

References

See also