Abstract:
A device for sustaining a plasma in a torch is provided. In certain examples, the device comprises a first electrode configured to couple to a power source and constructed and arranged to provide a loop current along a radial plane of the torch. In some examples, the radial plane of the torch is substantially perpendicular to a longitudinal axis of the torch.
Abstract:
In an apparatus for determining characteristics of materials by photoreflectance the sample (62) is irradiated by light from a monochromatic light source (50, 51) and a pump beam source (63). The reflected ligth is analyzed by a detector (56), a lock-in amplifier (55), a A/D converter (66) and a computer (70). The d.c. signal of the detector (56) is kept constant for a certain measurement by means of a variable neutral density filter (58) in the monochromatic light beam. By varying the pump beam wavelength and its modulation frequency by the use of an acousto-optical modulator the component layers, their quality and the properties of the various interfaces in the sample (62) are determined.
Abstract:
Es wird eine Einrichtung zur optischen Trübungsmessung von Gasen, insbesondere zur Messung des Rußanteils in Abgasen von Dieselmotoren, beschrieben, die relativ einfach aufgebaut ist, betriebssicher arbeitet und insbesondere eine einfache Handhabung selbst bei unterschiedlich aufgebauten Meßobjekten ermöglicht. Dies wird erfindungsgemäß dadurch erreicht, daß ein mit einer Lichtquelle optisch gekoppelter Regelempfänger zur Regelung der Lichtstärke des Meßlichtstrahles vorgesehen ist, daß eine Abtast- und Halteschaltung vorgesehen ist, der die Werte eines Meßempfängers und des Regalempfängers im Zeitmultiplex zugeführt werden, wobei anschließend die Meßwerte in einer Recheneinheit weiterverarbeitet und die Regelwarte über eine Regelschleife der Lichtquelle zugeführt werden. Ferner ist die Recheneinheit zur Speicherung mehrerer Meßwerte bzw. Trübungsspitzenwerte und Mittelwertbildung der gespeicherten Spitzenwerte vorgesehen, wobei die Spitzenwerte mittels dynamischer Messung mit einer bestimmten Anzahl von Meßzyklen ermittelt werden. Außerdem ist eine Einrichtung vorgesehen, die der Recheneinheit motorbezogene Parameter zur Auslösung von Meßwertermittlung und Meßwertberechnung zuführt.
Abstract:
An optical analyzer for determining an analyte in a fluid of interest such as a body fluid of interest satisfying the foregoing need and embodying the present invention may include a housing (12); combination optically transparent cuvette and lancet (16) mounted removably in the housing (12), the cuvette (17) may receive an optically transparent reagent test system for reacting with the body fluid to produce a change in at least one optical transmissive characteristic of the system indicative of the analyte; a cuvette carrier (14) mounted slidably in the housing and for removably receiving the cuvette (17); a spring actuator (40) mounted in the housing and connected to the cuvette carrier (14), the spring actuator may be compressed and released to advance the carrier and thereby advance the lancet (16) into engagement with a portion of a body to produce the body fluid, and the spring actuator (40) retract the lancet (16) within the housing (12) after the advancement; depth control apparatus (70, 72) for controlling the depth of penetration of the lancet into the body portion; an electro-optical system (34, 36, 38) mounted in the housing in optical engagement with the cuvette (17) and for passing a light beam through the cuvette and the reagent system and for receiving the light beam modified by the change in optical transmissive characteristic of the system and for transmitting computation signals indicative of the analyte to a computer (22); a computer mounted in the housing for receiving the computation signals and for comparing the computation signals against predetermined data to produce display signals indicative of the analyte; a display (24) mounted in the housing and for receiving the display signals and for providing a visible display indicative of the analyte; and control switches (26) mounted in the housing and connected to the computer (22) for controlling the operation of the computer (22).