| 摘要 |
The invention relates to an electrochemical cell for measuring ion activity in a liquid sample, which consists of a measuring electrode and a reference electrode comprising an annular-gap diaphragm (12), a primary (5) and a secondary (15) electrolyte, a wick-like flow-limiting device (9) and a reference element (6). The annular-gap diaphragm is embodied as a removable sleeve (2) which seals off a filling chamber (14) of the secondary electrolyte towards the outside and towards the inside forms an annular gap (12) together with the measuring electrode. The preferred area of application of the invention is the exact measurement of the pH of aqueous solutions, very small quantities of a test sample being sufficient for such a measurement. |
