Define the working of pH Meter?

The pH of a solution, we know, measures the degree of acidity or alkalinity relative to the ionization of water sample. A pH meter is a sophisticated voltmeter capable of reading small millivolt changes from the pH electrode system. It is an electric device that measures pH using an electrochemical cell. The function of the pH meter is to measure the potential difference (in mV) between the electrodes and convert it to a pH display.