PH Meter Electrode for Laboratory

A pH electrode is a sensor that measures the potential of hydrogen ions (

) in a solution. It's made of a special glass that's sensitive to hydrogen ion concentration.

A pH electrode is made of two electrodes: a reference electrode and an indicator electrode.

• The reference electrode is kept at a constant potential by a salt bridge. 
   
• The indicator electrode is sealed with hydrogen-impermeable glass, except at the tip.
• When the electrode is dipped into a solution, hydrogen ions accumulate around the bulb and replace the metal ion from the bulb.