Abstract: A reference electrode for an electrochemical three-electrode sensor, including a shaft, a platinum electrode embedded in the shaft, a platinum oxide coat at least partially covering the platinum electrode, and a polyhydantoin coat completely covering the platinum oxide coat and any exposed surface of the electrode not coated with platinum oxide.

Abstract: An electrochemical sensor having at least two electrodes that communicate with a liquid measurement cell electrolyte and a housing that encloses the electrodes and the electrolyte. The surfaces of the electrodes facing the electrolyte bridge web connecting the electrodes are covered with a semipermeable membrane.

Abstract: The device for the simultaneous detection of dissimilar gas components contains a number of electrochemical, three-electrode measuring cells with a common electrolyte, that are formed from a number of working electrodes with a common counter-electrode and a common reference electrode. Measured values are generated with the aid of a potentiostatic evaluation circuit that also adjusts and sets the potentials at the working electrodes. The current signals correlated with the gas concentrations to be measured are displayed with the aid of current-measuring instruments 11.sub.1 . . . 11.sub.n in the lines to the working electrodes 5.sub.1 . . . 5.sub.n. At the same time it is important that all three-electrode measuring cells have a common counter-electrode 3 and a common reference electrode 4, and that the potentiostatic evaluation circuit 6 contains control loops 7.sub.1 . . . 7.sub.n which maintain the potentials of the working electrodes 5.sub.1 . . . 5.sub.

Abstract: The measuring apparatus is based on an electrochemical sensor with a hollow chamber connected upstream through which the gas to be measured diffuses to the sensor surface. A pump for introducing a rinsing gas is connected to the hollow chamber. Moreover, the rinsing gas connection is connected to a test gas source which produces a known concentration of the component to be measured. The function of the sensor may be controlled by connecting the test gas source. The accuracy of the measured values and thus the reliability of the measuring apparatus may be substantially improved by these measures.

Abstract: A sensor consists of a catalytically active measuring electrode communicating with a non-polarizable atmospheric oxygen electrode by way of an aqueous acid electrolyte. The electrolyte used is an aqueous gelatinous polymeric adhesive in which ionogenic substances are dissolved. Due to the adhesive properties of the electrolyte, a 3-phase boundary of air-catalyst-electrolyte is formed at the transition to the measuring electrode and substantially determines the measuring process.

Abstract: An apparatus for checking gas analysis devices in respect of their sensitivity and their response and regeneration behaviour with respect to time, wherein a reproducible quantity of the measurement component is produced at a predetermined production rate, for a period of time which is guided entirely or at a constant proportion as a concentration pulse to the measurement element of the gas analysis device. For the production of the measurement component a chemical or electro-chemical reaction or even a thermal reaction is used. The time interval can then be conveniently controlled. A decisive advantage with toxic measurement components is that the gas production takes place in all cases for only a short time during the test procedure.

Abstract: A method for checking gas analysis devices in respect of their sensitivity and their response and regeneration behaviour with respect to time, wherein a reproducible quantity of the measurement component is produced at a predetermined production rate, for a period of time which is guided entirely or at a constant proportion as a concentration pulse to the measurement element of the gas analysis device. For the production of the measurement component a chemical or electro-chemical reaction or even a thermal reaction is used. The time interval can then be conveniently controlled. A decisive advantage with toxic measurement components is that the gas production takes place in all cases for only a short time during the test procedure.

Abstract: An electrochemical gas detector based on an electrolytic measurement cell having a normally solid organic electrolyte. The gas component to be detected diffuses out of the gas chamber at a three phase border (electrolyte-electrode-gas chamber) and there causes a change in the electrochemical equilibrium. As a result in an outer closing circuit a measurable electrical current is produced. The electrolyte consists of an anhydrous organic gel with a very low vapor pressure. The gas chamber adjacent to the three phase border constitutes a partly sealed cavity, which is in communication with the gas atmosphere to be examined via an absorption filter selectively permeable to the measurement component. The length of the cavity is dimensioned so as to be so short that practically no back diffusion of the measurement component through the filter takes place.

Abstract: In the gas detector the gas stream to be investigated is conveyed past one of two electrodes of a measuring cell. The two electrodes are in contact with an electrolyte, wherein the electrolyte is an anhydrous organic gel. The gas component to be measured changes the electrochemical equilibrium at one of the two electrodes and produces thereby in the outer closing circuit a measurable electrical current which is a measure of the concentration of the gas component, to be detected.

Abstract: In a process for the determination of the inorganic carbon content of aqueous liquids, the sample to be examined, together with a carbon dioxide-free carrier gas, is introduced into a heated reaction chamber, where it is reacted with crystalline potassium bisulphate and/or a mixture of equal parts of potassium bisulphate and potassium sulphate to form carbon dioxide and water. The CO.sub.2 generated is analyzed quantitatively in a CO.sub.2 analyzer.