Reference electrode XR42 - S7 - Chauvin Arnoux

pH measurements with separate electrodes require the combination of a measuring electrode and a reference electrode. The latter will maintain a constant and stable potential during measurements.

- XR42 electrode is composed of a glass tube in which a drop of mercury and mercurous chloride (calomel) are placed in contact with a platinum wire. The reference element is filled with a saturated KCl solution (KCl 3 mol/L).

It is suitable for many applications except those where chloride ions could react with a compound present in the solution, such as with Ag+ ions which form a precipitate, AgCl. In this case, a reference electrode with mercurous sulfate is preferably used.