| 摘要 |
PURPOSE:To enable the accurate measurement of the concentration of a component to be measured without being affected by an inter-solution potential difference, by injecting a prescribed quantity of solution to be inspected into a measuring electrode tank and a reference electrode tank first and by measuring a potential difference between a measuring electrode and a reference electrode thereafter. CONSTITUTION:A measuring electrode 8 is constituted by a selective electrode responding to an active amount of a component to be measured, and a reference electrode 7 by a selective electrode responding to any one of components contained in a solution to be inspected. As to the state wherein the solution to be inspected is filled up in a reference electrode tank 4 and a measuring electrode tank 6 (two tanks are isolated from each other by a liquid junction element 9 of a porous body), a voltage between terminals of the electrodes 7 and 8 is measured 10. Under the control of an arithmetic device 14, subsequently, a prescribed quantity of standard solution 12 containing the component to be measured of high concentration is injected into the electrode tank 6 by an automatic buret 11 and mixed uniformly by an agitating device 13, and then a voltage between the terminals of the electrodes 7 and 8 is measured 10. By using a change in these voltages between the terminals and a gradient of a working curve of the electrode 8 determined beforehand, the concentration of the component to be measured in the solution to be inspected is calculated by the device 14. After the end of measurement, valves 15 and 16 are opened and the solutions inside the tanks are returned to a storage tank 1. |
