Abstract:
A method for controlling a spectrometer for analyzing a product includes steps of: acquiring a measurement representative of the operation of a light source, determining, depending on the measurement, a value of supply current of the light source, and/or a value of integration time of light-sensitive cells of a sensor, disposed on a route of a light beam emitted by the light source and having interacted with a product to be analyzed, and if the integration time and/or supply current value is between threshold values, supplying the light source with a supply current corresponding to the determined supply current value, adjusting the integration time of a light-sensitive cell to the determined integration time value, and acquiring light intensity measurements supplied by the sensor, enabling a spectrum to be formed.
Abstract:
A gas sensor for sensing a presence of ethanol vapor in a cabin includes a source of infrared radiation, a first detector configured to receive infrared radiation from the source in a first region of the electromagnetic spectrum and a second detector for detecting a parameter, such as an amount of radiation received from the source in a second region of the electromagnetic spectrum, a temperature of the source and/or an amount of a second gas present in the cabin, affecting the amount of infrared radiation detected by the first detector. With this data, the presence of ethanol vapor in a cabin is established by an output of the gas sensor based on signals from both the first and second detectors.
Abstract:
A method of determining a concentration of a gas in a sample and/or the composition of a gas using a spectrometer comprises transmitting of radiation whose wavelength substantially continuously runs through a wavelength range, wherein the continuous running through of the wavelength range is overlaid by a wavelength modulation; measuring of an absorption signal as a function of the wavelength of the radiation; converting of the absorption signal into first and second derivative signals; deriving of a first and a second measured gas concentration value from the first and the second derivative signals, respectively; and determining of the concentration and/or the composition of the gas from at least the first measured gas concentration value, wherein the wavelength modulation is adapted in response to a change of a state variable of the gas such that a ratio between the first and the second measured gas concentration values is kept substantially constant.
Abstract:
A device for sensing analyte concentration, and in particular glucose concentration, in vivo or in vitro is disclosed. A sensing element is attached to the distal end of an optical conduit, and comprises at least one binding protein adapted to bind with at least one target analyte. The sensing element further comprises at least one reporter group that undergoes a luminescence change with changing analyte concentrations. Optionally, the optical conduit and sensing element may be housed within a cannulated bevel.
Abstract:
Embodiments generally relate to a light source and methods for minimizing temperature sensitivity of a light source light source. In one embodiment a light source includes a light-emitting diode, a light beam having an optical axis, a photodetector and a polarizer. The diode is operatively configured to emit the light beam. The beam splitter, positioned to intercept the light beam, includes a first optical surface operatively configured to reflect a first portion of the light beam and to transmit a second portion of the light beam therethrough. The photodetector is positioned to capture the first portion of the light beam after reflection by the beam splitter and operatively configured to generate photocurrent proportional to an intensity of that captured first portion. The polarizer is positioned between the diode and the beam splitter, and is operatively configured to polarize the light beam along a polarization direction perpendicular to its optical axis.
Abstract:
The output of optical computing devices containing an integrated computational element can be corrected when an interferent substance or condition is present. The devices may comprise an optional electromagnetic radiation source; a sample detection unit comprising an integrated computational element and a detector configured to receive electromagnetic radiation that has optically interacted with the integrated computational element and produce a sample signal associated therewith; an interferent monitor located proximal to the sample detection unit, the interferent monitor being configured to produce an interferent signal associated with an interferent substance; and a signal processing unit operable to convert the interferent signal into an interferent input form suitable for being computationally combined with the sample signal, the signal processing unit being further operable to computationally combine the sample signal and the interferent input form to determine a characteristic of a sample in real-time or near real-time.
Abstract:
A method and apparatus is provided for concentration determination of at least one component in an acid catalyst for hydrocarbon conversion containing an unknown concentration of an acid, an acid-soluble-oil (ASO), and water. An instrument configured for measuring a property of the acid catalyst, has responsivities to concentrations of one of the acid, ASO, and water, substantially independent of the concentrations of the others of the acid catalyst, ASO, and water. A temperature detector is configured to generate temperature data for the acid catalyst. A processor is configured to capture data generated by the temperature detector and the instrument, and to use the data in combination with a model to determine a temperature compensated concentration of the one of the acid, the ASO, and the water. Optionally, one or more other instruments configured for measuring other properties of the liquid mixture may also be used.
Abstract:
The scattered light from the measurement target substance passes through a light receiving window, and is received by a detector for +θ scattered light and a detector for −θ scattered light which are arranged symmetrically to each other across an optical axis at an equal angle or an equal interval in a vertical direction. A light source is fixed by a light-source holder (that is a base member on which the light source is arranged), and the detectors are arranged on and fixed to a detector holder (that is a base member on which the detectors are arranged). In this manner, drift of the light quantity data caused by the thermal deformation of the optical system can be corrected by comparing values of the light quantity data of the detectors.