| 摘要 |
PURPOSE:To stabilize a liquid junction part within a short time by providing a stop valve to either one of a comparing electrode solution introducing pipe and an ion sample introducing pipe and connecting the pipe provided with the stop valve to the other pipe in a T-shape. CONSTITUTION:When a stop valve 18 is opened to drive a pump 12, the electrode solution from a comparing electrode solution tank 19 and the sample solution from a sample introducing port 11 are respectively sucked through introducing pipes 13, 14 to meet with each other at a junction part 17. At the confluent point of time, the valve 18 is closed to close the pipe 14. By this mechanism, the sample solution flows so as to tear off the end surface of the comparing electrode solution and, after tearing-off, the pump 12 is stopped. Since the comparing electrode solution uses the pipe 14 as a sleeve to come into contact with the sample solution only at an end surface part, a stable liquid junction is formed and the valve 18 is again opened to form the electric circuit of a comparing electrode 16 and an ion selecting electrode 15 and, by detecting the potential between the electrodes showing a steady valve, a stable liquid junction part can be formed within a short time. |
