Study On Automobile Emissions Test

China released GB18352.3-2005"Limits and measurement methods for emissions from light-duty vehicles (III, IV) "in 2005, it will be carried out in 2007.The third phase standard of emissions equals one of EU III.In order to adapt to new standard of emissions,try to control emissions,requires compile "coldstart emissions test process" about Euro III standard with normal temperature to test our car.Therefore the article focuses on compiling "coldstart emissions test process" about Euro III standard with normal temperature.Becouse the equipments often occur some troubles in testing prosesses,affects testing plan.The article advance how to improve emissions equipment test precision to sweep troubles,by analyzing factors of affecting equipments and summarizing former experiences.The factors of affecting emissions is quite complex.The article use existing equipments,correlation of emission maps with different spark timing and A / F ratio from an automotive gasoline engine was studied experimentally.The characteristics of spark timing and A / F ratio effect on HC,CO and NO_x emissions are analyzed through test data, these characteristics may be used to correct select or control the spark timing and A / F ratio for decreasing the exhaust emission of a gasoline engine.