A pH meter is used to acquire the measurement of a substance's pH level. The pH of a substance is a measurement of its acidity or basicity.
The pH level is used widely in chemistry and biology, and consists of a zero to 14 level system. Any pH below 7 is considered acidic, and any pH above 7 is considered basic, or alkaline. A pH of 7 is neutral, which is neither acidic or basic. A pH meter measures the pH level by testing the difference in electromotive force (electrical potential or voltage) between suitable electrodes placed in the solution.