A sensor platform for the assessment of the condition and quality of fluids while in service is based on a combination of solid-state light sources (LEDs) and detectors housed within a single integrated package. The sensor platform configured to be standalone in operation and comprises interfacing optics and acquisition and processing electronics. The sensor platform is configured to obtain inputs from multiple stimulus points and correlates these to changes in the overall composition or condition of the fluid. The sensing method can be described as a combination of a differential sensor, by monitoring changes from the normal status of the fluid, and an inferential sensor where changes are interpreted in terms of global impact rather than specific localized changes in component concentration.

A concentration measurement device 100 includes a light source 22 for generating incident light to a measurement space 10A, a photodetector 24 for receiving light emitted from the measurement space, and an arithmetic control circuit 26 for calculating a concentration of a measurement fluid on the basis of an output of the photodetector, and the light source includes a first light-emitting element 22a for generating light having a first wavelength, and a second light-emitting element 22b for generating light having a second wavelength, and the concentration measurement device is configured so as to calculate the concentration using either light of the first wavelength or the second wavelength on the basis of the pressure or temperature of the measurement fluid.

An apparatus for measuring a spectrum includes a light source array configured to emit light towards an object, a photodetector configured to detect light reflected by the object; and a processor configured to measure, using the light source array and the photodetector, a plurality of temperature correction spectra based on a temperature change of the light source array, obtain a light source temperature drift vector by analyzing the measured plurality of temperature correction spectra, measure, using the light source array and the photodetector, an analysis spectrum by using the light source array and the photodetector, and adjust the measured analysis spectrum to reduce an effect of the temperature change of the light source array by using the obtained light source temperature drift vector.

A system and method for the real time determination of microbial growth in or on perishable products. The system can predict the extent of microbial growth, e.g., whether food is spoiled, in real time by measuring chemicals released, e.g., CO.sub.2, from the perishable product during microbial growth. The output from a sensor can be correlated to the extent of microbial growth, i.e., spoilage, and provide information about the extent of microbial growth to the user, for example, through their smart devices.

A device for optical detection of analytes in a sample includes at least two optoelectronic components. The optoelectronic components include at least one optical detector configured to receive a photon and at least one optical emitter configured to emit a photon. The at least one optical emitter includes at least three optical emitters disposed in a flat, non-linear arrangement, and the at least one optical detector includes at least three optical detectors disposed in a flat, non-linear arrangement. The at least three optical emitters and the at least three optical detectors include at least three different wavelength characteristics.

The concentration measurement device 100 includes an electric unit 20 having a light source 22 and a photodetector 24, a fluid unit 10 having a measurement cell 1, optical fibers 11 and 12 for connecting the electric unit 20 and the fluid unit 10 and is configured to measure the concentration of the fluid in the measurement cell by detecting the light incident from the light source 22 to the measurement cell and then emitted from the measurement cell by the photodetector 24, where optical connection parts 32 and 34 connected to the optical fibers 11, 12 and the light source 22 or the photodetector 24 are integrally provided in the electric unit 20.

A Fourier transform infrared spectrometer (FTIR) includes: an infrared light source; an interferometer; a semiconductor laser for position reference of a movable mirror thereof; and a computer that performs Fourier transformation to a detected signal of an infrared interference wave from a sample to calculate a spectrum based on a memorized wavelength of the semiconductor laser and a detected value of a laser interference wave by a laser detector. The computer executes a program for calculating a spectrum of a solid reference sample, interpolating the spectrum of the reference sample in a wavenumber region of a unique peak, reading out a wavenumber of the unique peak based on a data after interpolation, and updating the wavelength of the semiconductor laser used in Fourier transformation such that the read-out value of the wavenumber falls within a specific range having an original wavenumber of the unique peak as a reference.

A spectral imaging system configured to obtain spectral measurements in a plurality of spectral regions is described herein. The spectral imaging system comprises at least one optical detecting unit having a spectral response corresponding to a plurality of absorption peaks of a target chemical species. In an embodiment, the optical detecting unit may comprise an optical detector array, and one or more optical filters configured to selectively pass light in a spectral range, wherein a convolution of the responsivity of the optical detector array and the transmission spectrum of the one or more optical filters has a first peak in mid-wave infrared spectral region between 3-4 microns corresponding to a first absorption peak of methane and a second peak in a long-wave infrared spectral region between 6-8 microns corresponding to a second absorption peak of methane.

The present description relates to a stabilized interferometric system comprising: a light source (210) for emitting an initial beam of coherent light; a spatial light modulator (220) configured to receive at least a first part of said initial beam and input data (203) and configured to emit a spatially modulated beam resulting from a spatial modulation of a parameter of said first part of said initial beam based on said input data; a scattering medium (230) configured to receive said spatially modulated beam; a detection unit (240) configured to acquire an interference pattern (IN.sub.0) resulting from the interferences between randomly scattered optical paths taken by the spatially modulated beam through the scattering material; a control unit (250) configured to vary the frequency of the laser source in order to at least partially compensate a change in said interference pattern resulting from a change in at least one environmental parameter.

There is provided an apparatus including a measuring unit including a light-emitting unit and a first sensor for measuring a first measurement value of a first physical quantity that varies in response to light emitted from the light-emitting unit passing through a measurement target; a second sensor for measuring a second measurement value of a second physical quantity having a correlation with a standard value of the first measurement value, among physical quantities relating to the measuring unit; a third sensor for measuring a third measurement value of a third physical quantity having a correlation with the standard value; a detection unit for detecting presence or absence or a concentration of the gas to be detected in the measurement target, based on the first measurement value; and a determination unit for determining whether a deterioration amount of accuracy of the first measurement value has exceeded a threshold.