METHOD FOR MEASURING NUMBER OF FINE PARTICLES IN ULTRAPURE WATER, FILTRATION DEVICE FOR MEASURING NUMBER OF FINE PARTICLES, METHOD FOR MANUFACTURE THEREOF AND HOLLOW FIBER FILM UNIT FOR USE IN THE DEVICE

摘要

A method for measuring the number of fine particles in ultrapure water, characterized in that it comprises a step of subjecting the ultrapure water to a pressurized filtration by the use of a hollow fiber film having a skin layer capable of capturing fine particles in the ultrapure water at least on the inner surface thereof, a step of exposing the above inner surface of the hollow fiber film, and a step of determining the number of fine particles present on the above inner surface exposed.