What is pH sensor & How does it work?

A pH sensor is a device used to measure the pH level, which indicates the acidity or alkalinity of a solution. pH is measured on a scale of 0 to 14, with 7 being neutral, values below 7 indicating acidity, and values above 7 indicating alkalinity.
How a pH Sensor Works:
Ion Exchange at the Glass Electrode: The glass electrode in the sensor has a thin glass membrane that allows hydrogen ions from the solution to interact with it. This creates a potential (voltage) that changes depending on the concentration of hydrogen ions in the solution.
Reference Electrode: The reference electrode provides a stable reference point by maintaining a constant potential, usually using a solution like potassium chloride.
Measurement of Voltage: The pH meter measures the difference in potential (voltage) between the pH electrode and the reference electrode. This difference in voltage is directly related to the hydrogen ion concentration in the solution.
Conversion to pH Value: The meter converts the measured voltage difference into a pH value, based on the Nernst equation, which describes the relationship between ion concentration and electric potential.