pH electrode / pH sensor

The pH electrode, also known as a pH sensor, is a measuring instrument used to determine the pH value of a solution. The pH value indicates the concentration of hydrogen ions (H⁺) and is a measure of the acidic or basic character of a solution. Typically, the measuring range is between 0 (very acidic) and 14 (very basic), whereby a pH value of 7 is considered neutral. A pH electrode / pH sensor consists of two main components: the glass electrode and the reference electrode. The glass electrode is sensitive to hydrogen ions and generates a potential that is proportional to the H⁺ concentration. The reference electrode serves as a stable reference point. Modern pH sensors combine both components in one housing, which makes them compact and easy to handle.

The pH electrode / pH sensor is equipped with a special glass membrane that is selectively permeable to H⁺ ions. Inside the glass electrode is a buffer solution with a known ion concentration. When the electrode is immersed in a solution, a voltage difference occurs at the glass membrane, which is measured with a pH meter. This value is converted into the corresponding pH value and displayed on the pH meter, e.g: PCE-PH 228 series.