PH Meter is Their Function
In an aqueous solution, free hydrogen and hydroxide ions are present in acids and bases, respectively. As a general rule, a solution is considered basic when it contains more hydroxide ions than hydrogen ions, and acidic when the opposite is true. A pH meter measures the acidity or basicity of a solution by inserting an electric probe into the sample. The two electrodes in a pH meter are the "sensor" and "reference" electrodes, respectively. Both are constructed using a silver wire that has been coated in silver chloride. Each set has a glass tube with a buffer solution (pH 7) and a glass tube with saturated potassium chloride. The sensor electrode is a small bulb-shaped piece of glass membrane doped with silica and metal salts. This membrane is extremely flimsy to lessen the wind resistance it creates. This bulb is dipped into the test fluid to determine the pH level. In a solution, hydrogen ions replace part of the metal ions in the bulb. Drift velocity for ...