Abstract:
The present invention relates to a method for monitoring and control of smeltmetallurgical processes, endothermic as well as exothermic ones, preferably pyrometallurgical processes, by means of optical spectrometry, whereby one first determines for each endothermic and exothermic smeltmetallurgical process and/or process step characteristic emissions or absorptions and identifies the atomic or molecular origin of the emissions/absorptions, that one during a running process records changes in the characteristic emissions/absorptions and relates these changes to the condition of the process and with reference hereto controls the process.
Abstract:
Color former is added to blood serum sample color it, and measurements for specific components are determined based on the light absorbance caused by coloring. For one sample, a differential light absorbance between two wavelengths at each of long wavelength region, middle wavelength region and short wavelength region within a visible wavelength band is determined. The degree of chyle is determined from the measurements for the long wavelength region, the degree of hemolysis is determined from the measurements for the middle wavelength region, and the degree of icterus is determined from the measurements for the short wavelength region. The measurements for the specific components are then corrected by the degree of chyle, degree of hemolysis and degree of icterus to obtain highly correct measurements.
Abstract:
A plurality of test tubes containing specimens are passed successively through a predetermined position. Two monochromatic beams are transmitted alternately along a single path through said predetermined position and through each of the test tubes passing through said predetermined position. The characteristics of the two beams are such that one of them is capable of being absorbed by the specimen and the other substantially incapable of being absorbed. Thus it is possible to obtain an electric signal representing the ratio or difference between electric signals corresponding to said two monochromatic beams.
Abstract:
A beam of light passes through a sample and the transmitted light beam is detected by a detector. The light beam to be detected by the detector is a monochromatic light beam obtained by a dispersing means and the wavelength of the monochromatic light beam is continuously varied by a wavelength scanner. A transparent plate is obliquely positioned in the path of the monochromatic light beam so that the detector delivers an electrical signal representative of the absorption when the transparent plate lies in the path of the light beam and another electrical signal representative of the absorption when the transparent plate does not lie in the path of the light beam. A ratio detector or a difference detector compares these electrical signals with each other or subtracts one of these electrical signals from the other thereby obtaining a differential spectrum.
Abstract:
Un objet de l'invention est un procédé de mesure d'une quantité (ex ) d'une espèce gazeuse (Gx ) présente dans un gaz, l'espèce gazeuse étant apte à absorber une lumière dans une bande spectrale d'absorption (Δχ) le procédé comportant les étapes suivantes : a) disposition du gaz entre une source de lumière (11) et un photodétecteur de mesure (20), la source de lumière (11) étant apte à émettre une onde lumineuse incidente (12), l'onde lumineuse incidente se propageant à travers le gaz vers le photodétecteur de mesure (20); b) illumination du gaz (G) par la source de lumière (11); c) mesure, par le photodétecteur de mesure (20), d'une intensité, dite intensité de mesure, d'une onde lumineuse (14) transmise par le gaz, dans une bande spectrale de mesure, comportant la bande spectrale d'absorption (Δχ); d) mesure, par un photodétecteur de référence (20ref ), d'une intensité dite intensité de référence, d'une onde lumineuse (12ref ) de référence, l'onde lumineuse de référence étant émise par la source de lumière (11) dans une bande spectrale de référence (Aref ); les étapes b) à d) étant mises en oeuvre à une pluralité d'instants de mesure (1... k... K), le procédé comportant, à chaque instant de mesure : e) à partir de l'intensité de référence mesurée par le photodétecteur de référence, et de l'intensité de mesure (l(k)) mesurée par le photodétecteur de mesure, estimation d'une absorption (abs(k)) de l'onde lumineuse incidente (12) par le gaz; f) estimation d'une quantité (ex (k)) de l'espèce gazeuse (Gx ), à partir de l'absorption estimée lors de l'étape e); le procédé étant caractérisé en ce que l'étape e) comporte une prise en compte d'une fonction de correction (S), représentative d'une variation temporelle d'une intensité de l'onde lumineuse incidente (12) dans la bande spectrale de mesure (.120 ) relativement à une intensité de l'onde lumineuse incidente (12) dans la bande spectrale de référence (Àref ); et en ce que la fonction de correction (8) est préalablement établie au cours d'une phase de calibration, comportant les étapes suivantes : cal-i) disposition d'une source de lumière de test (111), face à un photodétecteur de mesure de test (20'), et face à un photodétecteur de référence de test (20'ref ), la source de lumière de test, le photodétecteur de mesure de test et le photodétecteur de référence de test étant respectivement représentatifs de la source de lumière (11), du photodétecteur de mesure (20) et du photodétecteur de référence (20ref ); cal-ii) illumination du photodétecteur de mesure de test et du photodétecteur de référence de test par la source de lumière de test, durant des instants de calibration s'étendant selon une période de calibration; cal-iii) comparaison d'une évolution temporelle de l'intensité détectée par le photodétecteur de mesure de test, dans la bande spectrale de mesure, avec une évolution temporelle de l'intensité détectée par le photodétecteur de référence de test (l'ref(k)), dans la bande spectrale de référence (Àref ).
Abstract:
Disclosed is an apparatus for determining a concentration of a substance in a liquid medium of a test sample. The apparatus comprises a light source (22; 02) for directing a light beam of a first wavelength range towards the test sample, and a first detector (24; 120) for measuring intensity of irradiation emitted from the liquid medium at a second wavelength characteristic for the liquid medium. The apparatus further comprising a second detector (26; 116) for measuring intensity of irradiation emitted from the substance at a third wavelength characteristic for the substance, and a determining unit (50; 150) for determining the concentration of the substance in the liquid medium based on the measured intensities of the irradiation collected at the second wavelength and at the third wavelength. Further, the apparatus is arranged such that the irradiation collected by the first detector is emitted from a first surface area of the test sample and the irradiation collected by the second detector is emitted from a second surface area, which first and second areas are at least partly covered by a surface area of the test sample illuminated by the light beam of the light source.
Abstract:
Methods and systems for measuring one or more properties of a sample are disclosed. The methods and systems can include multiplexing measurements of signals associated with a plurality of wavelengths without adding any signal independent noise and without increasing the total measurement time. One or more levels of encoding, where, in some examples, a level of encoding can be nested within one or more other levels of encoding. Multiplexing can include wavelength, position, and detector state multiplexing. In some examples, SNR can be enhanced by grouping together one or more signals based on one or more properties including, but not limited to, signal intensity, drift properties, optical power detected, wavelength, location within one or more components, material properties of the light sources, and electrical power. In some examples, the system can be configured for optimizing the conditions of each group individually based on the properties of a given group.
Abstract:
Techniques for optical detection of target chemicals on/in samples using differential spectral measurements and a compact, non-contact optical measurement system are disclosed. Light of at least two different wavelengths, or different bands of wavelengths, interacts with a target chemical, and at least some of the light that has interacted with the target chemical is incident on at least two photodetectors. Each of the photodetectors is configured to detect light of a different wavelength, or a different band of wavelengths, that has interacted with the target chemical. A processing logic is configured to compute a ratio between a parameter indicative of the intensity of light detected by one photodetector and a parameter indicative of the intensity of light detected by the other photodetector, and to determine the presence and/or the amount of the target chemical based on the computed ratio.
Abstract:
An interference fringe pattern generator form's an interference fringe pattern from the light rays diffused from a region of an object positioned against a background. A planar array of detector pixels is arranged to capture an image of the interference fringe pattern. A storage medium records information indicative of intensity values of the image of the interference fringe pattern captured by a selected group of pixels of the planar array of detector pixels. The information is recorded as a function of the optical path difference values traversed by the diffused light rays through the interference fringe pattern generator for each of the pixels in the selected, group of pixels. A processor determines the spectral characteristics of the object based on the information indicative of the intensity values recorded by the storage medium and the optical path difference values traversed by the diffused light rays.