Before using it for electrochemistry purposes, are there any tests that we should perform to make sure that the reference electrode is working properly?
In the occasion where, there is a lack of any other (extra) RE (reference electrode), then you might like to use a simple (pure>3N, and clean surface) Ag-wire in 3M-KCl electrolyte and measure OCPwire/RE (0 ± 20 mV)[1] with an electrometer[2].
1. The OCP value should be less than 20 mV (ideally it should be zero) https://www.researchgate.net/post/how_i_can_know_Ag_AgCl_refrence_electrode_is_ok_or_not
2. We can, also, use impedance spectroscopy. A RE is good if it has low Zreal~1 kOhm, and very low Zimag~
Dear Dr. Khantesh Agrawal,
test your Ag/AgCl reference electrode with an additional standard reference electrode of the same type (or a calomel reference electrode) in a small beaker containing 3 M NaCl. Connect both the electrodes to voltmeter.
Read the potential difference between the electrodes on the voltmeter. Theoretically the difference between two electrodes of the same type would be zero. However, in actual practice there is commonly some variation. If the two electrodes are of the same type (e.g., Ag/AgCl vs. Ag/AgCl) the voltmeter should read 0 ± 20 mV. If your reading for any pair of electrodes is significantly different, you should have another electrode of the same type handy to help distinguish which of the two is bad. If you compare an Ag/AgCl reference electrode to a standard calomel electrode (SCE), link the SCE at the black (negative) input on the voltmeter. The voltmeter should then read -35 ± 20 mV.
For more details, please see at:
https://www.gamry.com/application-notes/instrumentation/reference-electrodes/
and
https://www.gamry.com/support/technical-support/frequently-asked-questions/reference-electrode-overview-and-care/
Best regards, Pierluigi Traverso
In the occasion where, there is a lack of any other (extra) RE (reference electrode), then you might like to use a simple (pure>3N, and clean surface) Ag-wire in 3M-KCl electrolyte and measure OCPwire/RE (0 ± 20 mV)[1] with an electrometer[2].
1. The OCP value should be less than 20 mV (ideally it should be zero) https://www.researchgate.net/post/how_i_can_know_Ag_AgCl_refrence_electrode_is_ok_or_not
2. We can, also, use impedance spectroscopy. A RE is good if it has low Zreal~1 kOhm, and very low Zimag~
Dear Khantesh Agrawal ,
In addition to the open circuit potential OCP, you can evaluate the liquid junction resistance, the reference potential, the liquid junction potential and the polarization.
Below is the reference that describes these tests. It was written in Brazilian Portuguese, but I believe it is worth translating.
Silva Jr., AI; Araujo F., HC; Silva, RC Performance tests for electrodes: Reference eletrodes. Quimica Nova, v 23 (2000) pp. 512-517. https://doi.org/10.1590/S0100-40422000000400014
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