The reflex reflector, stripped of all removable parts, or the lamp with which the reflex reflector is grouped or reciprocally incorporated, shall be subjected to the action of a saline mist for a period of 50 hours, comprising two periods of exposure of 24 hours each, separated by an interval of two hours during which the sample is allowed to dry. The saline mist shall be produced by atomizing, at a temperature of 35 ± 2 čC, a saline solution obtained by dissolving 20 + 2 parts by weight of sodium chloride in 80 parts of distilled water containing not more than 0.02 % of impurities.