Definitions for "Reference electrode"
Reference electrode is an electrode whose potential is known and against which potentials of other electrodes can be measured. The potential of a reference electrode is completly independent of the analyte concentration. Table: Potential of a reference electrodes Potential vs. SHE, V Calomel electrode Ag / AgCl T, °C 0.1 M 3.5 M Saturate 3.5 M Saturate 15 0.3362 0.254 0.2511 0.212 0.209 20 0.3359 0.252 0.2479 0.208 0.204 25 0.3356 0.250 0.2444 0.205 0.199 30 0.3351 0.248 0.2411 0.201 0.194 35 0.3344 0.246 0.2376 0.197 0.189
the half of an electrode pair which provides a constant potential, regardless of the sample composition. The potential developed by a sensing electrode is measured against this reference to give a signal, which can be converted to the activity of ion under analysis. Single junction reference electrodes have a single chamber generally filled with a potassium chloride solution saturated with silver chloride, which contacts with the sample solution through a single liquid junction by means of a semi-porous ceramic plug or fritted disc. Double junction reference electrodes have two chambers with the internal reference system having a liquid junction with an intermediary salt bridge and then a second liquid junction to the external sample. The outer filling solution is chosen to avoid contamination of the sample and minimize the effects of the liquid junction potential.
a complete half - cell, maintaining a stable potential
the reference element of an electrochemical cell.