How does a pH electrode work?
The pH value defines the activity pH+ of the hydrogen ions in a liquid. The numerical value is the result of negating the decimal logarithm of the number of free hydrogen ions. Or, to put it simply: pH 7 is neutral; i.e. there are no free H+ ions in the water. If the range is below pH 7 there are superfluous H+ ions and the water is acid. At values above pH 7 there is a deficiency of H+ ions and we speak of caustic or alkaline water. The fact that ions are charged particles (H+) is used to determine their number. The + indicates that there must be a positive charge in case of an abundance of H+ ions. If we create a reference point the tension, which depends on the number of H+ ions, can be measured. This gives us the pH value. The reference point is an element contained in the defined electrolytic solution and which is integrated in the EHEIM pH electrode. The contact with the measuring medium is made through a porous, permeable component. The pH electrode supplies a tension, which dep
