| 摘要 |
PURPOSE:To obtain a measured value having high reliability by providing a means for bypassing and supplying ultra-pure water and a means for washing a water tank in the sample intake port of an Na<+> ion electrode meter. CONSTITUTION:Ultra-pure water 37 is supplied from a water feed section 30 to a water tank 1 and thereafter the air in the atm. is supplied to a bubble generating section 5 for specified time at a specified flow rate from an air feed section 40 and is bubbled in the water 37. The water is discharged at a specified rate into a draining section 50 after the end of bubbling and Na<+> ions are measured with an Na<+> ion electrode meter 13. While the bubbling is effected, the ultra- pure water is supplied at a specified rate from a system 70 for bypassing and supplying the ultra-pure water into the sample intake port 13a of the meter 13 by which the concn. of the Na<+> ion in the ultra-pure water is measured without using bubbling to stabilize the background value of the Na<+> ion electrode meter. Washing is accomplished by supplying the ultra-pure water to the tank 1 via a washing system 60 to clean the tank after the pure water used for bubbling is discharged thereby removing the residual Na<+> ions in the water tank. |
