20
Measuring pH
To measure pH with a conven-
tional glass pH electrode, the
meter uses a pH-sensing glass
bulb that is sensitive to hydrogen
ions. The potential developed at
the glass membrane is directly
related to the pH of the solution.
The glass electrode is paired
with a reference electrode
which completes the electrical
measuring circuit and provides
a stable reference point. These
two electrodes are joined to
create a combination electrode.
The combination glass electrode
is connected to the pH meter
which reads the voltage, converts
it to pH units, and displays the
result.
Reference
Electrode
Porous
Junction
(Diaphragm)
pH Sensor
Temperature sensor
with automatic temperature
compensation (ATC)