| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a system for measuring a carbon dioxide concentration in water, by which a decrease in the measurement accuracy caused by the deterioration of a pH indicator can be corrected. <P>SOLUTION: The carbon dioxide concentration measuring system 1 includes a deterioration determining unit 31 whereby a change rate ΔA<SB>0</SB>in the isosbestic point absorbance A<SB>0</SB>is measured and, when the change rate ΔA<SB>0</SB>becomes equal to or lower than a predetermined decrease rate, it is determined that a pH indicator solution is deteriorated. After the determination of the deterioration of the pH indicator solution by the deterioration determining unit 31, a pH value calculating unit 27 calculates the pH value of the pH indicator solution in accordance with a correction pH operational expression by which the deterioration is corrected with the use of the change rate ΔA<SB>0</SB>in the isosbestic absorbance A0. <P>COPYRIGHT: (C)2009,JPO&INPIT |
