Abstract: The present invention relates to a method and a measuring arrangement for the non-destructive detection of coating errors in an electrically conductive substrate layer, which is coated with at least one electrically insulating cover layer. An input signal is inductively or capacitively input into the electrically conductive substrate layer by means of a signal input device. A measurement signal is output from the substrate layer via the cover layer by means of a signal output device. An evaluation unit is used to evaluate the output measurement signal. In this case, a coating error is detected when a signal parameter change of a signal parameter of the output measurement signal exceeds an adjustable threshold value.

Abstract: The aim of the invention is to create a novel conversion layer, the properties of which regarding breakability, decorative effect, and mechanical abrasion are at least not worse than those of previously known conversion layers. Said aim is achieved by providing the inventive conversion layer with at least one doped siliceous layer that is obtained by applying at least one alkaline siliceous solution which additionally contains aluminum ions and/or ions of at least one B-group element and/or ions of at least one lanthanide and/or ions thereof, which have been complexed with at least one complexing agent, and/or at least one organic polar compound. The novel conversion layer can be used as a corrosion-proof and abrasion-proof protective coating for technical parts and/or for decorative purposes.

Abstract: The invention relates to a method for treating metallic surfaces consisting of zinc, magnesium or aluminium or of the alloys of zinc, magnesium or aluminium, to which lacquer, coatings of plastic material, paint, sealants or adhesives are applied after treatment. The treatment of the metallic surfaces takes place at between 10° C. and 100° C. by immersion, spraying or rolling with an aqueous solution. The solution has a pH of between 2 and 13 and contains one or more compounds of the type XYZ at a concentration of between 10−5 and 1 mol/l. Y is an organic group containing between 2 and 50 C atoms and has a straight-chain structure. X is a COOH, HSO3, HSO4, (OH)2PO, (OH)2PO2, (OH)(OR′)PO or (OH)(OR′)PO2 group. Z is a OH, SH, NH2, NHR′, CN, CH═CH2, OCN, epoxy, CH2═CR″—COO, acrylamide, COOH, (OH)2PO, (OH)2PO2, (OH)(OR′)PO or (OH)(OR′)PO2 group. R′ is an alkyl group with between 1 and 4 C atoms.