Reference electrode BR42 - 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 the measurements.

It consists 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 (3 mol/L KCl).

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

The choice of the reference electrode mainly depends on the experimental conditions of your measurements.