How to check ph meter digital reference electrode

(1) ph meter digital internal resistance inspection method

Using a laboratory conductivity meter, one end of the electrode socket of the conductivity meter is connected to a reference electrode, and the other end is connected to a metal wire. The reference electrode and the metal wire are immersed in the solution at the same time, and the measured internal resistance should be less than 10kΩ. If the internal resistance is too large, it means that the liquid junction is blocked and should be dealt with.

(2) ph meter digital electrode potential check

Take a good reference electrode of the same model and the reference electrode to be tested and connect them to the input terminals of the pH meter, and then insert KCl solution (or buffer solution with pH=4.00) at the same time, and the measured potential difference should be -3 ~3mV, and the potential change should be less than ±1mV. Otherwise, the reference electrode should be replaced or regenerated.

(3) ph meter digital visual inspection

The silver-silver chloride filament should be dark brown, if it is off-white, the silver chloride has been partially dissolved.