Calomel sleeve junction electrode

A calomel sleeve junction electrode can provide low junction potential while adding a small amount of potassium chloride electrolyte to the sample and thereby reducing its resistance. Some users reduce the concentration of the normally saturated KCl filling solution to 0.1 M KCl in order to minimize the junction potential and to decrease stabilization time. This electrode potential is listed in Table 3.5. 

Rgure 2.3. Schematic cross-section representation of the construction of some typical commercial calomel electrodes A) fiber or porous-ceramic Junction type and (B) ground glass-sleeve type. The electrolyte leak rate of the fiber or porous-ceramic junction type is quite low, typically 1-10 fJ/Ar that for the sleeve type around 100 ft//Ar. 

Reference electrode A potentiometric half-cell, comprising an inner element, usually calomel or silver-silver chloride, a chamber containing the appropriate filling solution, and a device forming a liquid junction between the filling solution and the sample (e.g., a fritted disk, a ground glass sleeve, or a narrow-bore hole). 

---