| 摘要 |
<P>PROBLEM TO BE SOLVED: To keep the classification characteristics of ultrafine particles constant. <P>SOLUTION: A slip correction coefficient is calculated using a temperature of a gas passing an impactor portion 13 and a pressure of the gas in the upstream or downstream of the impactor portion 13. Then, an average flow rate at an outlet of a nozzle 131 of the impactor portion 13 is calculated using a mass flow rate of the gas passing the impactor portion 13 and a pressure of the gas. A 50% cutoff particle diameter d<SB POS="POST">50</SB>in the compactor portion 13 is determined using the calculated slip correction coefficient. The mass flow rate of the gas passing in the impactor portion 13 is controlled so that the 50% cutoff particle diameter d<SB POS="POST">50</SB>approaches a set value. <P>COPYRIGHT: (C)2012,JPO&INPIT |
