Definition - What does Reference Electrode mean?
A reference electrode has a known electrode potential and is stable. Its high stability is achieved by employing the redox system, which must contain saturated concentrations in each of the participating solutions of the reaction.
Uses of reference electrodes are numerous, but the most important of all is in the electrochemical cell. This is where it's used as a half cell in the electrochemical cell to allow for the determination of the other half's cell potential. They are also used in electrochemical measurements and devices like the DPV and electrochemical biosensor, respectively.
Reference electrodes can be classified as aqueous, calomel, non-aqueous and own-constructing.
Corrosionpedia explains Reference Electrode
The most common aqueous reference electrodes used include:
· Standard hydrogen electrode
· Normal hydrogen electrode
· Saturated calomel electrode
· Reversible hydrogen electrode
· Silver chloride electrode
· Copper-copper sulfate electrode
· PH electrode
· Dynamic hydrogen electrode
· Palladium-hydrogen electrode
The copper-sulfate reference electrodes have three advantages over other electrodes. They have a Lexan tube, a strong top can and a CPT ceramic plug. These CPT plugs have numerous advantages, namely:
· Uniform and controlled CPT porosity
· The capability of fast wetting, thus making the electrode usable within minutes of filling. This is incomparable to others like wooden plugs that can take hours.
· Low electrical resistance due to pre-heating on the condition that the plug is kept moist in the saturated copper-sulphate solution.
· The drying and wetting process has the same low resistance.
· Covering the CPT plug when not in use is not necessary, although it is highly recommended.
· It is housed in a high-density polythene fitting for protective purposes against breaking or chipping.
Non-aqueous reference electrodes include the quasi-reference electrodes which are made fresh for any given experiment. This reduces the problems that come with poor storage and maintenance. They are cheaper than other types of reference electrodes. Pseudo-reference electrodes do not maintain their potentials. For one to use this type of reference electrode, affecting conditions must be known and calculated.