Abstract: A diffusion collector for analytes contained in liquid phases includes a planar housing which has channel-like cavities. A collecting phase is inserted into these channel-like cavities. The collecting phase is covered by a diffusion membrane through which the analyte can pass. The housing has at least one incoming pipe and one outgoing pipe allowing the fluid medium to pass through the channel-like cavities perpendicular to the direction of diffusion.

Abstract: The invention concerns a cation-selective sensor provided with a cation-selective coating and based on the fact that analyte ions present in a solution cause detectable changes in the electrical characteristics of the layer. The acid/base components in the cation-selective layer render the sensor function independent of the anions present in the analyte solution. This improves the measurement accuracy and lowers the detection threshold.

Abstract: The invention concerns an analyte selective sensor for the qualitative and/or quantitative determination of ions or substances contained in solution. The proposed sensor (1) comprises at least one analyte-specific layer (3) deposited on an inert carrier (7) and in contact with the solution; this analyte-specific layer consists of a liquid, solid or semi-solid material and is in contact with at least two electrodes (5, 6). The layer (3) selectively removes the analyte from the solution so that its own electrical characteristics, such as resistance, conductivity, admittance or impedance, change as the analyte is taken up.

Abstract: There are proposed a method and a device for ascertaining the surface condition, particularly of traffic routes, as regards dryness, wetness or icing, in which the surface is irradiated by a radiation source with an infrared component, and the reflected radiation is measured simultaneously in different wavelength ranges characterizing water and ice. In this case at least four wavelength ranges are selected, permitting sufficient depth or penetration of the radiation into the surface. A first and a second wavelength range are so selected that they are influenced to a very small degree by absorption of the water molecules, and a third and fourth wavelength ranges are so selected that they are characteristic for water and ice. The influence of the background on signals measured in the third and fourth wavelength ranges is compensated for by means of the information in the signals measured in the first and second wavelength ranges.

Abstract: Device for prolonging the effective usage time (service life), arrangement and process for minimizing temperature effects in any ion-selective polymer membrane electrode measuring chain (ISPE measuring chain), wherein one solution or both solutions directly adjoining the polymer membrane (outer measuring solution and inner potential drain solution) are saturated or supersaturated with the compounds which normally tend to bleed out; and wherein the isotherm intersection of an ion-selective measuring chain with redox drain elements is optimally located in the middle of the measuring range such that this middle is located at ca. 0 mV.The device may be used for monitoring of groundwater with opposite changes in the concentrations of nitrate and ammonium, evaluated in a special device, with electronic data processing and intermediate data storage (in RAM pack) at the site of the measurement and data polling as needed to a central unit by telemetry.

Abstract: In the atomic absorption or atomic fluorescence spectroscopy the problem exists to compensate the background absorption. For this purpose a measuring light beam, which is passed through a sample space, is frequency modulated by using the Doppler effect. This is achieved in that devices for generating a rate of change of the optical path length passing between two points of this path of rays of the measuring light beam (12) are provided in the path of rays of the measuring light beam (12). Different constructional solutions herefor are described. The optical path length can be varied cyclically by movable mirrors. But it is also possible to arrange a crystal (132) in the path of rays, the refractive index of which can be varied cyclically by applying an electric voltage to the field plates. (134 and 146).

Abstract: In spectrographic measurements, the selectivity (that is to say, the ratio of the signal from the analytical sample to the signal from the impurity) is of vital importance. If a narrow spectral band is filtered from the region of the spectrum to be examined by means of a filter arrangement or the like and supplied to a detector whose output signal is displayed, there is a substantial improvement in selectivity in that the filter apparatus is periodically displaced relative to the region of the spectrum to be examined, that the spectral band extending through the filter apparatus is periodically displaced over the range of the spectrum to be examined and that the output signal for the detector is transmitted to the display through a lock-in-amplifier whose phase-reference signal is proportional to the displacement.