Method and apparatus for calibrating a pH/ISE meter

摘要

Apparatus for calibrating a pH/ISE meter includes a solution chamber for receiving a standard pH/ISE electrode adjustably suspended in the chamber. Inlets are provided into the chamber so that a wash solution and buffers may be introduced into the chamber by gravity, the introduction of these liquids being controlled by valves controlled by a controller. The chamber also has a drain outlet which is opened and closed by a similar valve under the control of the controller. The controller controls the valves in a pre-determined sequence to flush and fill the chamber first with a wash solution, and then with buffers so that the electrode is immersed in each buffer long enough to enable an associated pH/ISE meter to obtain a stable reading of the pH/ISE value of the buffer. After the final buffer has been emptied from the chamber, the controller controls the valves to flush and fill the chamber with a solution. The controller may also include provisions for introducing into the chamber a specimen solution whose pH/ISE value is to be determined and measuring the value of that solution. Alternatively, the electrode in the chamber may be removed and placed in a separate sample chamber to be read by the calibrated pH/ISE meter. A calibration method is also disclosed.