Abstract: A program controlled dishwasher in which magnetic sensors provided adjacent to the dishwasher door respond to magnetic fields of predetermined polarization provided by permanent magnets in a catenulate magnetic key mounted on a dishwasher caddy in a position adjacent the magnetic sensors when the caddy is in the tub of the dishwasher, for generating a verifiable code pattern readable against dishwasher stored programs for the selection and actuation of a program specific to the articles which are stored in the caddy for washing. The polarization patterns on the caddies are specific to the kind of articles stored therein and may be readily altered to accommodate different articles.

Abstract: A black body radiator for calibrating infrared measuring devices in the form of a heatable body is heated by means of a heating foil in the form of a metallic electrically excellently conducting heating coil embedded in a plastic sheet. The heating foil is adhered in excellently thermally conductive manner to a rear surface of the heatable body of the black body radiator. At a slight distance from and slightly inclined to the heating foil surface an infrared-radiation-reflecting mirror is arranged. The mirror reflects the radiation coming from the heating coil and incident thereon into the intermediate spaces of the heating coil so that the radiation passes through the heating foil and is absorbed by the rear side of the black radiator. The intermediate space between the heatable body and the mirror is evacuated. Furthermore, the rear side of the mirror and a holder are provided with a thermal insulation, for example in the form of ceramic paper.