1. Make sure the electrode is free from contamination and it is clean.
  2. To achieve equilibrium, immerse the electrode in a 3M (KCl/NaOH) solution.
  3. Choose the standard reference electrode with known potential.
  4. As illustrated in Fig 1, place both electrodes in a cell containing saturated 3M (KCl/NaOH) and connected to a voltmeter. It is useful for determining the potential of the reference electrode.
  5. If the voltage value is zero, the reference electrode is functioning properly.
  6. If the voltage value is non-zero or near to zero, the difference is very small and it may be acceptable.
  7. If the voltage value fluctuates more than usual (unstable), take it into consideration, and then verify the concentration of the filling solution to restore the electrode’s condition

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