| 摘要 |
PURPOSE:To make measurement by previously forming the calibration curve of a flat band potential Efb of a metal oxide having semiconductor-like properties and the pH of a soln. CONSTITUTION:An electrochemical cell 9 is constituted of a pH sensing electrode 6 consisting of the semiconductor of the metal oxide, a reference electrode 8 and a counter electrode 7 consisting of platinum. A potentiostat 10 is connected between the electrode 6 and the electrode 8 so as to apply a potential difference therebetween. A lock-in-amplifier 11 which allows arbitrary selection of the frequency for measuring AC resistance and the phase difference between the current and voltage by passing AC current between the electrode 6 and the counter electrode 7 is inserted between said electrodes. The potentiostat 10 is preferably connected to a commercially marketed personal computer for the purpose of taking in, analyzing, computing, displaying or printing of data. The pH of the high-temp. high-pressure aq. soln. is thus measured. |
