GAMRY Reference Electrodes Electrodes (Aqueous reference electrodes)

Aqueous reference electrodes:

- Saturated Calomel (Hg2Cl2): The saturated calomel electrode (SCE) is the most popular reference electrode. It has a reputation of being very stable and robust.

- Silver/Silver Chloride (Ag/AgCl): The Ag/AgCl reference electrode is simpler in construction than the SCE and it contains no mercury. It is a very stable reference electrode.

- Mercury/Mercurous Sulfate Reference Electrode (Hg/Hg2SO4):  The Hg/HgSO4 reference electrode uses a filling solution of potassium sulfate. The Hg/HgSO4 reference electrode is recommended when chloride ion cannot be tolerated in the electrolyte.

- Mercury/Mercury Oxide (Hg/HgO): Non-Aqueous reference electrode - a reference electrode based on the reaction between elemental Mercury and Mercury Oxide. Filled with potassium hydroxide (20% w/w). Electrode potential is 98 mV vs. Normal Hydrogen Electrode (NHE)

- Silver/Silver Nitrate non-aqueous reference electrode (Ag/Ag+): The Ag/Ag+ reference electrode requires user assembly. It consists of a silver wire and one gram of silver nitrate powder. The AgNO3 powder should be dissolved in an appropriate electrolyte. Ideally, this electrolyte is the same as that used for the analyte (to eliminate junction potentials), an acetonitrile-based electrolyte can generally be used.