| 摘要 |
PURPOSE:To lessen production of harmful components in the human body, semiconductor silicon wafer and the like and improve safety. CONSTITUTION:Gad mixed with fine particles is supplied to an upstream part of a test filter 4 and the number of the particles across the test filter 4 is measured. An SiO2 production part 2 for producing SiO2 (quartz) fine grains on the upstream part of the test filter 4 is provided and the SiO2 fine grains produced from the SiO2 production part 2 are used as the fine particles. |
