How much do you know about the working principle of pH meter
The pH meter uses the potentiometric method to measure the pH value of the solution. Therefore, the working method of the pH meter can not only measure the pH value of the solution, but also measure the electromotive force of the battery. In Latin, pH is the abbreviation of Pondus hydrogenii, which is the activity of hydrogen ions in the substance, and the pH value is the negative number of the logarithm of the hydrogen ion concentration.
The main measuring parts of the pH meter are the glass electrode and the reference electrode, the glass electrode is sensitive to pH, and the potential of the reference electrode is stable. Put the two electrodes of the pH meter into the same solution together to form a primary battery, and the potential of the primary battery is the algebraic sum of the potentials of the glass electrode and the reference electrode.
The potential of the reference electrode of the pH meter is stable, so when the temperature remains stable, the potential change of the primary battery composed of the solution and the electrode is only related to the potential of the glass electrode, and the potential of the glass electrode depends on the pH of the solution to be measured Therefore, by measuring the change in potential, the pH value of the pH solution can be obtained.
