Water Quality And Water Quality Display - Yamato Pure Line WL320A Instruction Manual

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Table Of Contents

Table of Contents

Measuring the electric conductivity (conductivity)

The Water Quality Display of operation panel shows the electric conductivity at the outlet of ion

exchange resin cartridge. Use the displayed reading as a guideline to determine the cartridge

replacement timing. Read the conductivity while the electrode is fully immersed in water, that is,

while the deionized water is flowing.

Correct reading cannot be made in the following cases because of failure of immersion of

electrode into the water or the effects of air bubbles:

1. During initial operation period and while the unit is down

2. Immediately after replacement of ion exchange resin cartridge and the pretreatment cartridge.

Electric conductivity (conductivity)

・ The electric conductivity is the numerical value representing the easiness of the material to

conduct electricity. Water tends to conduct electricity more readily with increasing content of

dissolved electrolyte, that is, impurities. The numerical value of such conductivity decreases with

decreasing content of electrolyte.

・ The smaller numerical value of electric conductivity means higher purity of pure water.

Note however that the numerical value of electric conductivity refers only to electrolyte and not

to non-electrolytes (organic and colloidal substances, dissolved gases, microorganisms). The

value does not represent the total purity and should be handled only as one of indices to

represent the water purity.

・ The resistivity (R) is a factor representing the content the same as for the electric conductivity

（ρ）. Since the resistivity is the reciprocal of electric conductivity, the higher numerical value of

resistivity means higher purity.

Ｒ[Ω・ｍ]＝

Accordingly, factors for the theoretical pure water are defined as follows:

Ｒ＝１８．２×１０

ρ＝０．０５５×１０

Water quality of deionized water

Deionized water

Water with the lowest electric conductivity can be obtained by eliminating most of

electrolytes in water, except that non-electrolytes can be removed. More or less

deterioration of purity may be observed immediately after replacement of resin or at

resumption of water flow after shutdown of the system.

ρ[Ｓ/ｍ]

４

Ω・ｍ（１８．２ＭΩ・ｃｍ）２５℃

－４

Ｓ／ｍ（０．０５５μＳ／ｃｍ）２５℃

4.Operation Method