Abstract:
Ein Verfahren zur Untergrundbestimmung und- Korrektur von breitbandigem Untergrund, ist gekennzeichnet durch die Schritte: Glätten der aufgenommenen Spektralkurve; Bestimmen aller Werte der ursprünglichen Kurve, deren Wert über dem Wert der geglätteten Kurve liegt, und Reduzierung dieser Werte auf den Wert der geglätteten Kurve; wenigstens zweifaches Wiederholen der Schritte und Subtraktion der auf diese Weise erhaltenen Untergrundkurve von der ursprünglichen Kurve. Das Glätten der Kurve kann mittels Moving Average erfolgen. Die Breite des Moving Average kann das Doppelte einer durchschnittlichen Linienbreite einer Referenzlinie betragen.
Abstract:
Ein Verfahren zur Wellenlängenkalibrierung von Echellespektren, bei denen sich die Wellenlängen auf eine Mehrzahl von Ordnungen verteilen, ist gekennzeichnet durch die Schritte: Aufnehmen eines linienreichen Referenzspektrums mit bekannten Wellenlängen für eine Vielzahl der Linien, Bestimmen der Lage einer Vielzahl von Peaks des Referenzspektrums in dem aufgenommenen Spektrum, Auswählen von wenigstens zwei ersten Linien mit bekannter Ordnung, Lage und Wellenlänge, Bestimmen einer Wellenlängenskala für die Ordnung, in welcher die bekannten Linien liegen, durch eine Fitfunktion λ m (x), Bestimmen einer vorläufigen Wellenlängenskala λ m±1 (x) für wenigstens eine benachbarte Ordnung m±1 durch Addition/Subtraktion einer Wellenlängendifferenz Δλ FSR , die einem freien Spektralbereich entspricht nach λ m±1 (x) = λ m (x) ± Δλ FSR , mit Δλ FSR =λ m (x)/m, Bestimmen der Wellenlängen von Linien in dieser benachbarten Ordnung m±1 mittels der vorläufigen Wellenlängenskala λ m±1 (x), Ersetzen der vorläufigen Wellenlänge von wenigstens zwei Linien durch die nach Schritt (a) vorgegebene Referenzwellenlänge dieser Linien, und Wiederholen der Schritte (d) bis (g) für wenigstens eine weitere benachbarte Ordnung.
Abstract:
The invention relates to a spectrometer, which comprises a suspension mechanism (3) for its dispersive element (2), said suspension element pretensioning the spectrometer in an idle position, in addition to a deflecting device, which retains the dispersive element (2) in a deflected position, in such a way that a balance of forces occurs between the retaining force and the pretensioning force. This permits the dispersive element (2) to constantly return to the position defined by the retaining force after impacts or vibrations. An inventive spectrometer therefore comprises a dispersive element (2) and a suspension mechanism (3) for bearing the dispersive element (2) and for pretensioning the latter in an idle position using a pretensioning force, if the dispersive element (2) is in a deflected position. A control device (7) controls a retaining device (6a, 6b), to vary the deflected position, so that different spectral components can be recorded by a detector (9) of the spectrometer.
Abstract:
The present invention provides a method and apparatus incorporating a spinning, oscillating or stepping optical interference filter (109) to change the angle at which light (102) passes through the filters after passing through a sample (105) under analysis downhole. As each filter is tilted, the color or wavelength of light passed by the filter changes. Black plates are placed between the filters to isolate each filter's photodiode. The spectrometer of the present invention is suitable for use with a wire line formation tester to provide supplemental analysis and monitoring of sample clean up. The present invention is also suitable for deployment in a monitoring while drilling environment. The present invention provides a high resolution spectometer which enables quantification of a crude oil's percentage of aromatics, olefins, and saturates to estimate a sample's gas oil ratio (GOR). Gases such as CO2 are also detectable. The percentage of oil-based mud filtrate contamination in a crude oil sample can be estimated with the present invention by using a suitable training set and chemometrics, a neural network, or other type of correlation method.
Abstract:
An interference filter transmission wavelength scanning photometer wherein the angle of inclination of an interference filter (3) is periodically varied, the wavelength of the light to be transmitted is modulated with the periodical variation centered at the maximum absorption wavelength of the component to be measured, the variation of the intensity of the light transmitted through a sample is extracted by an infrared sensor (11) as an electrical signal, the time between the rise and fall zero cross points of the AC component of the electrical signal is determined by a microprocessor (16), the ratio (full period - 2 x half period)/(full period) is calculated from the full and half periods determined from the determined time, and the concentration of the component to be measured is determined from the variation of the result of the calculation of the ratio, thereby quantitatively determining the component without being influenced by the disturbance coexistent components.
Abstract:
A robust, compact spectrometer apparatus for determining respective concentrations or partial pressures of multiple gases in a gas sample with single as well as multiple and even overlapping absorption or emission spectra that span a wide spectral range. Embodiments may include at least a scanning mirror or diffraction grating (46) and a beam splitter (44) for dviding and dispersing a collimated input beam (40) into plural bands may include, for example, infrared bands of 3 to 5 micrometers and 7 to 10 micrometers.
Abstract:
The present invention concerns a spectrometer comprising means for producing a parallel beam from a light source whose spectrum is to be measured and directing it to an orientable grating (10) which produces a diffracted beam, means for focusing said diffracted beam to a detector (18) which measures the power of a selected line of the spectrum (1), said means comprising a reflector (12), and means for measuring the wavelength of the selected line. The means for measuring the wavelength comprise a reference light source producing a reference spectrum (3), comparison means for comparing the wavelength of the measured reference spectrum (1) with the stored reference spectrum (3), means for rotating the grating (10) providing a coarse positioning of the diffracted beam relatively to the detector (18) and measuring the grating position, and means for rotating the reflector (12) providing a fine positioning of the diffracted beam relatively to the detector (18) and measuring the reflector (12) position.