Ion Selective Electrodes; Fig. 4 Structure Of Combination Type Ion Selective Electrode; Table 3 Electrode Types - Horiba Scientific 6560S-10C Instruction Manual

I
on selective electrodes
The ion concentration is measured as the potential difference between an ion
selective electrode and a reference electrode which are soaked into the sample
solution and connected with an ion meter or a meter with an ion measurement
function. The function of each electrode is shown in the table below.
The method of measuring ion concentration using two electrodes in this way is
called the ion electrode method.
Electrode type
Ion selective
electrode
Reference
electrode
The following figure shows the structure of a combination type ion selective
electrode where two electrodes are integrated.
Reference electrode
Ion selective electrode
(Ion electrode tip)
56

Table 3 Electrode types

An electromotive force is generated through the ion
selective membrane by the difference of the ion
concentration between in the internal solution and in the
sample solution.
This maintains a stable potential no matter what kind of
sample solution or standard solution is present.
Fig. 4 Structure of combination type
ion selective electrode
Electrode function
Internal solution (ion electrode tip)
Internal solution (reference electrode)
Sample solution
liquid junction
The internal solution is discharged
to the sample solution.
Ion selective membrane