The pH sensor consists two electrodes in order to make a complete circuit to create electricity flow through the test solution. Both the electrodes are glass electrodes which has a silver alloy electrical wire and one of them is submerged in a neutral solution of potassium chloride contained inside a special glass bulb. This electrode works as the measuring system. The other electrode is situated in the outer case, filled with same neutral solution of potassium chloride, which works as a reference system. Both the electrodes are wired together to create a complete circuit. When the probe is dipped into the solution it calculates the pH by measuring the difference between the electrical charge formed in the measuring solution and the charge in reference solution.