What is a pH Meter? A pH meter is an electronic instrument used to measure the acidity or alkalinity of a solution. The pH scale ranges from 0 to 14 , where: pH < 7: Acidic pH = 7: Neutral pH > 7: Alkaline (Basic) A pH meter is an essential analytical instrument used to determine the acidity or alkalinity of a solution by measuring the hydrogen ion activity. Although its operation may appear simple from the outside—displaying a numerical pH value on a screen—the internal functioning of a pH meter is based on complex electrochemical principles. Understanding how a pH meter works requires knowledge of electrodes, ion exchange processes, reference systems, calibration methods, temperature effects, and signal conditioning performed inside the meter. How a pH Meter Works A pH meter measures the voltage difference between two electrodes: Glass Electrode: Detects hydrogen ion activity in the solut...