How to measure electrode potential using a pH meter
A pH meter is mainly used to measure the pH value of liquid media, but it can also be used to measure the ion electrode potential MV value when paired with a corresponding ion selective electrode. MV value refers to a potential signal value obtained by the pH electrode from the measured liquid hydrogen ion concentration based on electrochemical reactions, corresponding to pH=7-MV/59.
1. Turn on the power switch and the instrument enters pH measurement mode; Press the "Mode" button continuously (four times) to enter mV measurement mode for the instrument;
2. Clamp the ion selective electrode (or metal electrode) and the reference electrode on the electrode holder;
3. Clean the electrode head with distilled water, and then clean it once with the tested solution;
4. Insert the plug of the ion electrode into the measuring electrode socket;
5. Connect the reference electrode to the reference electrode interface at the back of the instrument;
6. Insert two types of electrodes into the tested solution, stir the solution evenly, and the electrode potential (mV value) of the ion selective electrode can be read on the display screen, and the ± polarity can also be automatically displayed.
7. If the measured signal exceeds the measurement (display) range of the instrument, or if the measuring end is open circuited, the display screen will show 1-- mV and trigger an overload alarm.
When measuring electrode potential using a metal electrode, use a Q9 plug with a clamp. Connect the Q9 plug to the measuring electrode socket and connect the clamp to the metal electrode wire; Alternatively, an electrode converter can be used, with one end of the electrode converter connected to the measuring electrode socket, and the metal electrode connected to the converter connector. Connect the reference electrode to the interface of the reference electrode.
