The number of diesel construction engineering machines approaches to one hundred thousand, and most of them belong to the higher age machines（from 11 to 20 years, about 41.7%）.The exhaust emission in the construction engineering machines include Particulate Matter（PM）、Nitrogen Oxides（NOx）、Polycyclic Aromatic Hydrocarbons （PAHs）、traces of Dioxin and other pollutants, which are harmful to human health. In order to control the pollutant emissions of diesel construction engineering machines, the plan divides into two aspects and proposes control strategy, inclusive of the imported and the in-use. Related to imported diesel construction engineering machines, the plan refers to the control methods of Europe, the United States, Japan and Hong Kong, as well as the recommended contents of commissioners, then introduces stages of standard. The plan has drawn up a draft, the Regulations Governing Issuance, Revocation, and Cancellation of Emissions Certificate of Conformity for Diesel and Alternative Clean Fuel Engine Construction Engineering Machines （draft）. The objects of draft are carbon monoxide（CO）, hydrocarbons（HC）, nitrogen oxides （NOx）, fine particulate matter（PM）, and so on . Related to in-use diesel construction engineering machines, the plan refers to the Free Acceleration Smoke Test of Japan, and conducts 53 sets of smoke tests. That finishes drawing up the method, the standard of pollutants from diesel-propelled engine of construction engineering machines. It is estimated that the future failure rate is about 20.4%. Among of particulate matters emitted from diesel construction engineering machines, PM2.5 is about 78.7% or more. For the purpose of improving emission of PM2.5 and smoke, it can be with the aid of maintenance and installation of diesel particulate filter. Maintenance involves adjusting injection nozzle and injection pump, and so forth. The improvement rate of opacity is about 23.9%~56.5%, and the improvement rate of PM2.5 is about 21.3%~34.3%. In addition, the maintenance cost is about 53,000~58,000. On the other hand, by installing the diesel particulate filter, the improvement rate of opacity is about 79.7%~100%, and the improvement rate of PM2.5 is about 42.7%~98.4%. Besides, the filter price is about 210,000~250,000. However, it must beware of its durability and addition of low-ash oil when using filters. The Environmental Protection Agency roughs in the certification mechanism of diesel particulate filters immediately to facilitate the following promotion and use. In summary, the plan estimates that the cost effectiveness of maintenance and installation of the diesel particulate filter. It will be reduced by 1438.4 g and 767.2 g TSP for each cost of $ 10,000.

Off-road diesel engine, Emission Inspection, Fine Particulate Matter（PM2.5）