Siemens Aktiengesellschaft

Jacky Vanhumbeeck

Hubert De Steur

Laurent Danneels

Guido Heyneman

Chris Vandenbossche

Frank Vangaever

Luc Boone

Egon Bussmann

Johannes Helder

Christiaan Vandenbossche

Bruno Flamme

Christian Vandenbossche

Luc Demaegd

A method for determining current efficiency in a galvanic bath employs a measuring cell within which a sample is introduced from the galvanic bath. In this sample, onto a preferably rotating electrode metal is precipitated. A negative voltage is applied at constant current during a first predetermined time during the precipitating. Thereafter, the precipitated layer is anodically eroded by use of a suitable electrolyte solution upon pole-reversal of the DC voltage. The current efficiency is then calculated.

Method for determining current efficiency in galvanic baths

An analysis system for determining total copper content in waste-water, as from a galvanizing system, comprises periodically taking samples from such waste-water, acidifying such samples with a metalliferous acid containing a metal which forms a strong cyanogen complex and which exhibits a larger electro-negative potential than copper, such as Pd, reducing cupric ions to cuprous ions, adjusting the pH of the resulting sample solution, adding a copper color-forming reagent, such as bathocuprione disulfonic acid salt, and determining the color content by colorimetry. In order to determine a reagent value, a prepared waste-water sample can be subjected to colorimetry before and after addition of the color-forming reagent.

Analysis system for determining copper content in waste water

An additive-free, fast-precipitating electrolyte bath for precipitating lustrous, crack-free palladium layers on workpieces is formulated, by successively adding to distilled water heated up to about 90.degree. C., phosphoric acid, sufficient ammonia to neutralize the phosphoric acid and palladium, in the form of palladium chloride. After dissolution of the palladium salt, the operating pH value is adjusted by additions of ammonia or phosphoric acid as required and the volume of the bath can be increased as desired by additions of further distilled water. The bath can be filtered prior to use.

Additive-free, fast precipitating palladium electrolyte bath and process

A control apparatus for automatically controlling at least the concentration of copper-ions, hydroxyl-ions and formaldehyde-ions in an electroless copper plating bath and independently analyzing, displaying and replenishing the concentration of each such ions whereby a sample for each of the ions is discontinuously removed from the plating bath and diluted with a specific amount of water and, independently of one another, the copper-ion concentration is colorimetrically analyzed, displayed and replenished as needed, the hydroxyl-ion concentration is potentiometrically analyzed, displayed and replenished as needed and the formaldehyde-ion concentration is amperometrically analyzed, displayed and replenished as needed.

Control apparatus for automatically maintaining bath component

A method for the automatic, electro-chemical determination of the end point of titration utilizing an initial, continuous addition of the titrant, up to a predetermined value, followed by a step-by-step addition with a resting time inserted therebetween for stabilization of the solution is disclosed. As the titrant is being added to the bath sample in constant volume units, a measured value is formed after every such addition. The difference to the preceding measurement is determined and the three consecutive differences of greatest magnitude are utilized in a mathematical formula for calculating the end point. The titration ceases when the greatest difference lies between two lesser values.

Method for the automatic electro-chemical determination of the end point

An automated analysis process and apparatus for analyzing the amount of dispersed water-immiscible solid organic substances in sewage water whereby a precise sample of sewage is taken from a sewage source, admixed with various reagent solutions, including a K.sub.2 Cr.sub.2 O.sub.7 --solution under heat-time conditions so that a reaction occurs between the sewage and the reagent and all of the organic substance in the sample are oxidized while simultaneously at least some Cr.sup.+6 --ions are reduced to Cr.sup.+3 --ions. During this oxidation-reduction reaction and at a location remote therefrom, a precise amount of Fe.sup.+2 --ions is generated within an aqueous acidic Fe.sup.+3 --ion containing solution via a coulometric reduction process. Thereafter, the reacted sewage-reagent solution is admixed and reacted with the so-generated Fe.sup.+2, Fe.sup.+3 --ion containing solution so that any residual Cr.sup.+6 --ions in the sewage-reagent solution are reduced to Cr.sup.+3 --ions and at least some Fe.sup.+2 --ions remain. By biamperometrically titrating the resultant Fe.sup.+2 --ion containing solution with a standardized Cr.sup.+6 -- ion containing solution, the precise amount of Fe.sup.+2 --ions within the titrated solution is determined and this provides an indirect indication of the amount of organic substances within the sewage sample. Pneumatic, hydraulic and electrical circuits actuate the various steps and are themselves actuated and controlled by a master control means, such as preprogrammed computer means, which also computationally integrates data from the overall process and automatically determines the amount of organic substances in the samples under analysis.

Process for the determination of the content of solid, dissolved and

A technique for the quantitative monitoring of a nonionic surfactant, such as nonylphenolpolyglycolether, in an acid tinning bath for the production of shiny, pore-free coatings on components. A measured amount of bath fluid (a bath specimen) is diluted with distilled water and mixed with sulfuric acid, and this mixture is then immediately titrated with a tannic acid solution until opalescence occurs.

Monitoring surfactant in electrolyte during metal treatment

A process control system for metal depositing baths for monitoring the chemical composition of a bath liquid provides that, in the event of a deviation of a component of the bath liquid from a reference value, the bath liquid is regenerated by supplying correcting liquid to the bath. The system includes an automatically operating analyzer which is connected to a measured value adjusting device which, in dependence upon the difference established between a reference value and an actual value of the bath liquid component subject to analysis, controls the supply of the correcting liquid to the bath. A common process control system for a plurality of galvanic baths includes a main programmer, a bath selection programmer and analysis programmers which can be selectively connected by the selection programmer, and which in accordance with the individual components of the bath liquid which is to be analyzed, actuate specific analyzer sections of the analyzer where each measured value adjusting device which is connected to an analyzer section will, in the case of a difference in measured value, control the supply of the correct quantity of the specific correcting liquid to the particular bath which is subject to analysis.

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Brugge, Belgium

Jacky Vanhumbeeck