Method for measuring the number of fine particles in ultrapure water and method for manufacturing a filtration device for measuring the number of fine particles in ultrapure water

摘要

A method for measuring the number of fine particles in ultrapure water includes subjecting the ultrapure water to internal pressure filtration through a hollow fiber membrane having a skin layer capable of trapping the fine particles in the ultrapure water at least on an inner surface thereof, exposing the inner surface of the hollow fiber membrane, and measuring the number of fine particles on the exposed inner surface.