COMPARISON STUDY ON CHARACTERISTICS OF NANO-SIZED PARTICLE NUMBER DISTRIBUTION BY USING CONDENSATION PARTICLE COUNTER CALIBRATED WITH SPRAY AND SOOT TYPE PARTICLE GENERATION METHODS

Abstract

In the year 2011, the Particle Measurement Program (PMP) in Europe started the regulation of the diesel vehicle's nano-sized particle number density (PN) due to its high degree of harm to the human body. Concretely, the standard level of PN emission was introduced in the Euro 5+ and 6 emissions regulation with a limit (<6.0 x 10(11)#/km) for diesel light-duty vehicle. Therefore, the determination of suitable and sophisticated instruments for reliable particle sampling and analysis was essential in taking exact experimental data. Now, among the PN emission measuring devices suggested by the P1V1P, condensation particle counter (CPC) is a key equipment for measuring the particle number density in real time and it has been used extensively. However, CPC can cause different results depending on operating conditions of the saturator and condensation that induce different rates of particle growth. This study was conducted to analyze the effect of CPC calibrated by a two-particle gelierator with spray and soot type methods applied on the nano-sized particle distribution's parameters such as number concentration and linearity. Also, in order to ensure the reliability for particle sensor system named as PPS, which had emerged as a useful diagnostic to making spatially and temporally resolved quantitative measurements of diesel PN concentration, it was compared with calibrated CPC system. As a result, nano-sized particle measuring system with CPC calibrated by spray type particle generator had a much higher counting efficiency, indicating a larger nano size available than soot type particle generator. And, comparative experimental results on the correlation between the particle number of CPC to a reflectance PPS system showed that above 5,000 #/cm(3) in number concentrations measured by CPC as well as PPS were found to be similar with good linear relationship.