SPECIFIC RESISTANCE ADJUSTING METHOD OF ULTRAPURE WATER, AND ULTRAPURE WATER TREATMENT APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a specific resistance adjusting method of ultrapure water capable of simply adjusting and stabilizing the specific resistance of ultrapure water greatly varying in a flow rate to a desired value, and an ultrapure water treatment apparatus.;SOLUTION: The specific resistance adjusting method of ultrapure water is provided, wherein the pressure of supplied carbon dioxide gas is adjusted and supplied to a motor-driven rotary valve when dissolving carbon dioxide gas into ultrapure water for adjusting the specific resistance, carbon dioxide gas corresponding to the rotational speed of the motor-driven rotary valve is supplied to a gas-liquid contact chamber, the specific resistance of the ultrapure water discharged from the gas-liquid contact chamber is measured, the rotational speed of the motor-driven rotary valve is adjusted by feedback of the measured specific resistance, and the specific resistance of the ultrapure water after dissolving of the carbon dioxide gas is set to a constant level in a range of 0.2-1.0 MΩ cm. The ultrapure water treatment apparatus suited to the specific resistance adjusting method is also provided.;COPYRIGHT: (C)2011,JPO&INPIT