摘要：In the vehicle emission test, there are many kinds of measurement equipment for particulate matter, and their measurement principles are also different. By using two kinds of equipment with different principle of particle measurement, the difference of measurement results under the same conditions is compared and the reasons are analyzed. The results show that more particles with particle size less than 50 nm are measured by DC principle, and the concentration of particles with small particle size is higher, so that the PN measurement results using DC principle test are higher than those using CPC principle test results.The measurement results of the CPC and DC principle test equipment during the transient process are very similar, but DC is more sensitive to small-particle particle testing and can test small-particle particles up to 10 nm, so the test concentration is higher than that of CPC.
