| 摘要 |
PURPOSE:To enable measurement of a pH value with a simple operation, by measuring the potential of a pH sensor only at one point to prepare a working curve indicating a relation ship between a balanced potential value and the pH value. CONSTITUTION:A pH sensor 10 includes a conducting base body 11 and a film 13 having a reversible oxidation-reduction function at the exposed tip face of the base body 11. A hydrogen ion carrier film 14 is formed covering this film 13. Then, the sensor 10 is immersed into a measuring aqueous solution held din a container 21 together with a reference electrode 23, and the sensor 10 and the electrode 23 are connected to a potential difference meter 24. Hydrogen ions in the aqueous solution is transported quickly to the film 13 through a hydrogen ion membrane 14 and the membrane 13 causes an oxidation-reduction reaction to generate a potential corresponding to the concentration of hydrogen ions. This potential is measured with a potential difference mete 24 as difference from the potential of the electrode 23. The potential difference using the sensor 10 satisfies a linear relationship with the pH value and thus, working curve is prepared beforehand thereby finding the pH of the measuring aqueous solution. |
