Thalamid reference electrode

The reason that the Thalamid reference electrode is introduced here before the much more well-known Calomel reference electrode stems from its far superior temperature stability. It shows no temperature hysteresis up to 135°C, and in this respect is even superior to the Ag/AgCl reference electrode. As with the Ag/AgCl electrode, the reaction... 

TI+/TI(Hg) electrode — A -> reference electrode commonly known as Thalamid electrode employing thallium amalgam (40wt%) as electronically conducting phase and an aqueous solution of KC1 (saturated or 3.5 M) saturated with T1C1. In comparison with the saturated calomel electrode it shows a superior temperature stability up to T = 135 °C without temperature hysteresis, no disproportionation of T1C1 (as compared to Hg2 CI2) or significant complexation are found. 

The Tl(Hg)/TU reference electrode (Thalamid ) is said to be superior to either calomel or silver-chloride electrodes when measurements are made over a range of temperatures, because it attains its equilibrium potential very rapidly after changes in temperature. The half-cell can be written as... 

Some commercial glass pH electrodes use Thalamid electrodes as internal reference electrodes. 

Fricke [74] was the first to propose that this reversible and wide-ranging unpolarizable element be used as a reference electrode in conjunction with a KCl salt bridge. The Thalamid electrode of Jenaer Glaswerke Schott Gen, Mainz, [75] can be symbolized by ... 

All potentials refer to a standard hydrogen electrode in the used solvent. Exceptions are stated explicitly. This electrode is frequently called Thalamid -electrode. ... 

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