A pH meter is an electronic device used to measure the acidity or alkalinity of a solution. It provides a numerical value on a scale from 0 to 14, where 7 is neutral, values below 7 indicate acidity, and values above 7 indicate alkalinity. pH meters are commonly used in laboratories, agriculture, and aquariums to ensure optimal conditions for various chemical processes and living organisms. The device typically consists of a glass electrode and a reference electrode, which work together to determine the pH level. Regular calibration with standard solutions is necessary for accurate readings. pH meters are essential tools in fields such as chemistry, biology, and environmental science.