フィルタリーク試験に関する統計的考察 A Statistical Study on Filter Leakage Test
This study proposes a statistical leakage testing method for HEPA and ULPA filters used in cleanrooms. The method consists of two parts, scanning test and stationary re-measuring test. For scanning test, a high-speed and accurate method is proposed considering the influences of particles penetrating through the normal portion of filter and the discreteness of particle measuring. For stationary re-measuring test, a method to minimize the number of data is proposed by using Wald's theory. The validity of this method is investigated by Monte-Carlo simulation, and the influence of variance of parameters which is assumed to vary, is examined. It is concluded that the variance of probe scan speed and upstream particle concentration have a strong influence on the results of scanning test. It is also concluded that we can obtain stable and accurate result in stationary re-measuring, and it is indicated that by using this method a big hole can be readily ditected as a leakage point.
- エアロゾル研究 = Journal of aerosol research
エアロゾル研究 = Journal of aerosol research 14(2), 119-128, 1999-06-20