CONCENTRATION MEASURING METHOD FOR INORGANIC CARBON ACID DISSOLVED IN WATER

• Main Authors: FUJIYA CHINATSU, HARA HIROICHI, FUKUDA YOSHINORI, IKUTA YOSHIAKI, HANEDA MICHIO, KANEKO MASAHITO
• Format: Patent
• Language: English
• Published: 23.08.1994
• Edition: 5
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PURPOSE:To enable accurate and continuous real time measurement of concentration to be conducted by measuring the potential difference of a sample water having pH conditioned to a predetermined level using a carbon dioxide gas electrode and an ion meter. CONSTITUTION:A first peristaltic pump 12 feeds sample water. pH of the sample water is conditioned to a predetermined level by a buffer fed from a second peristaltic pump 14 and then the sample water is fed to a carbon dioxide gas electrode 18 where the concentration of carbon dioxide gas is measured. The electrode 18 has a container comprising an inner body 22, an outer body 24, etc., and an internal liquid 28 is encapsulated between the bodies 22, 24. Furthermore, a pH-responsive glass electrode 30 and a gas permeable Teflon membrane 32 are provided and a silver-silver chloride electrode 34 is disposed, as a reference electrode, in the internal liquid 28. The sample water permeates the Teflon membrane 32 and dissolved in the internal liquid 28. Consequently, pH of the internal liquid 28 varies to produce a potential difference between the electrodes 30, 34 which is detected by means of an ion meter 36. Concentration of inorganic carbon acid in the sample water can be measured based on a correlation working curve between the potential difference and the concentration of carbon dioxide gas.