Abstract: A multicomponent electrolyte with a defined potential and a display cell containing it. The multicomponent, liquid electrolyte is based on at least one metal iodide dissolved in an anhydrous organic solvent, and is characterized in that it comprises three functional components: a first metallic element M.sub.p yielding at least two iodides corresponding to different valences, and which is intended to ensure an equilibrium between the reduced forms of iodine I.sup.- and I.sub.3.sup.- ; an iodide of a second metal M.sub.t in a practically completely dissociated state, intended to fix the concentration of the anionic species I.sup.- in the electrolyte; and an iodide of a third metal M.sub.x constituting the display vehicle.

Abstract: A probe for selectively detecting a vapor component in a gaseous atmosphere in contact therewith. The probe includes a pair of measuring electrodes and a semiconductor layer which is coated with a dielectric layer. An auxiliary electrode is placed opposite the semiconductor layer so that the voltage can be varied and consequently the level of the average current can be adjusted. It is thereby possible to detect the concentration of a vapor component to be measured in the entire range and with the same sensitivity.

Abstract: A polarographic cell for measuring partial pressure of oxygen in a fluid in which the detector electrode and the reference electrode are immersed in an electrolyte at least partially absorbed in a rigid insulating material.

Abstract: Probe for selectively detecting polar molecules in a gaseous atmosphere in contact with the probe, characterized by a layer of semiconductor material covered by a film of dielectric material.

Abstract: Sensor for selectively detecting at least one constituent of a gaseous mixture in contact with the sensor. The sensor comprises a thin layer of a semiconductor material covered with a dielectric film formed with a large number of microscopic openings.