The device used to measure the pH of a solution is called a pH meter. This electronic instrument provides precise measurements of the acidity or alkalinity of a solution by detecting the concentration of hydrogen ions present. The pH scale ranges from 0 to 14, with values below 7 indicating acidity, 7 signifying neutrality, and above 7 representing alkalinity. pH meters typically consist of a glass electrode and a reference electrode that work together to provide accurate readings. Widely used in laboratories, industries, and environmental testing, pH meters have become essential tools for ensuring quality control and monitoring chemical processes.