Ultrapure water production facility and method of monitoring ultrapure water

A method of monitoring ultrapure water in which a portion of ultrapure water supplied from a production system to a use point is separated and a water quality thereof is monitored,

• wherein the separated ultrapure water is allowed to pass through a monitoring system comprising
• a first monitoring unit including a resistivity meter,
• a second monitoring unit in which one type or two or more types of measuring instruments, selected from the group consisting of a dissolved gas concentration meter, a TOC meter, a hydrogen peroxide concentration meter, a silica meter, a boron meter, an evaporation residue meter, and a water temperature meter, are connected in parallel,
• a third monitoring unit including a particle meter, the third monitoring unit being provided in parallel with the first monitoring unit and the second monitoring unit,
• a transportation pipe for introducing a portion of monitoring wastewater discharged from the first monitoring unit into the second monitoring unit, and
• a discharging pipe for discharging the remaining of the monitoring wastewater, and
• the first monitoring unit and the second monitoring unit are connected in series so that the water quality is monitored.

An ultrapure water production facility, comprising:

• an ultrapure water production system producing an ultrapure water;
• a use point where the ultrapure water is used for a predetermined usage;
• a supply pipe supplying the ultrapure water to the use point from the ultrapure water production system;
• a first monitoring unit including a resistivity meter;
• a second monitoring unit in which at least one measuring instrument selected from the group consisting of a dissolved gas concentration meter, a TOC meter, a hydrogen peroxide concentration meter, a silica meter, a boron meter, an evaporation residue meter, and a water temperature meter is connected in parallel, the second monitoring unit being provided in series with the first monitoring unit;
• a third monitoring unit including a particle meter, the third monitoring unit being provided in parallel with the first monitoring unit and the second monitoring unit;
• an extracting pipe branching off from the supply pipe, separating a monitoring water from the ultrapure water, and supplying the monitoring water to the first monitoring unit and third monitoring unit;
• a transportation pipe introducing a portion of the monitoring water discharged from the first monitoring unit into the second monitoring unit;
• and
• a discharging pipe discharging a remaining of the monitoring water not introduced to the second monitoring unit, to the ultrapure water production system.