Introduction
pH Meter Electrode working principle
(1) Internal reference electrode: it is a silver/silver chloride electrode, which is mainly used to draw electrode potential. It is required that the potential is stable and the temperature coefficient is small.
(2) Internal reference solution: internal reference solution with zero potential of 7pH. The specific solution is a mixed solution of neutral phosphate and potassium chloride. The glass electrode and the reference electrode constitute the pH of the battery to establish zero potential value mainly depends on the pH value of the internal reference solution and chloride ion concentration.
Electrode slope: theoretically, the slope of the glass electrode is 59.16mv at 25 ℃, that is, the glass electrode will produce a 59.16mv potential change every time the solution changes a ph value. However, in fact, all glass electrodes cannot reach the theoretical value of 100%. Generally, the electrode slope is more than 98% (percentage slope) of the theoretical value. In addition, the mv difference value corresponding to each unit of PH value has a certain change under different temperatures.
