Method and device for measuring fine particles in ultrapure water

摘要

A novel measuring method which allows measurement of fine particles which are extremely fine and contained in a very small amount in ultrapure water is provided. The number frequency with respect to the fine particles having a particle diameter of 0.1 mum or more is measured based on the finding that the fine particles contained in the ultrapure water at the use point of an ultrapure water production system exhibits a logarithmic normal distribution to determine the logarithmic normal distribution of the fine particles contained in the ultrapure water, and the number of the fine particles having a particle diameter of less than those of the measured particles contained in the ultrapure water is obtained from the distribution.