Abstract:
A sample analyzer comprising: a measuring part for measuring optical information of a sample at first wavelength, second wavelength, and third wavelength, first light of the first wavelength and second light of the second wavelength being absorbed by a second substance but substantially not absorbed by a first substance, and third light of the third wavelength being absorbed by the first substance; and an obtaining means for obtaining content of the first substance in the sample, and content of the second substance in the sample, influence by the second substance being excluded from the content of the first substance, based on the optical information at the first wavelength, second wavelength, and third wavelength measured by the measuring part.
Abstract:
Spectroscopic system and spectrometers including an optical bandpass filter unit having a plurality of bandpass regions and a spatial encoding unit for encoding discrete frequencies of light passing through the optical filter. The incorporation of the encoding unit allows the spectrometer system to use a detector having one or a small number of elements, rather than using a more expensive detector array typically used with filter-based spectrometers. The system can also include an integrating chamber that collects the light that is not transmitted through the bandpass filter unit, and redirects this light to strike the filter unit again, resulting in a significant increase in the optical power passing through the filter. The integrating chamber maximizes the return of the reflected light to the filter assembly and minimizes optical losses. The integrating chamber may be an orthogonal design to preserve the optical geometric characteristics of the light entering the chamber.
Abstract:
A sample placed under a microscope is illuminated by light from a laser beam. Raman scattered light is passed back via a dichroic filter to various optical components which analyse the Raman spectrum, and thence to a CCD detector. The optical components for analysing the Raman spectrum include tunable dielectric filters in a filter wheel; a Fabry-Perot etalon; and a diffraction grating. These various components may be swapped into the optical path as desired, for example using movable mirrors, enabling the apparatus to be used very flexibly for a variety of different analysis procedures. Various novel analysis methods are also described.
Abstract:
Apparatus for inserting and removing several filters from an optical path and for determining at all times the instantaneous positional relationship of each filter with respect to the optical path includes a set of filters mounted on a carrier which is attached to a resonant piezoelectric system, and further includes reference tracks also located on the carrier and extending in the direction of the oscillatory motion and including a sequence of binary indicia progressing in the direction of the oscillatory motion. The reference tracks are read optically to produce a series of binary electrical signals which are processed to yield the instantaneous position of the carrier and filters with respect to a fixed optical path.
Abstract:
Monochromatic infrared radiation of variable wavelengths between 1.0 and 3.5 microns is directed upon a portion of a moving web, and the spectra of infrared radiation reflected from the web portion and of radiation transmitted through the web portion are separately measured by sensors located on both sides of the web. These spectra are combined to provide an absorption spectrum insensitive to any elastic scattering that is also present. Measures of the contents of the web constituents are generated by least-square fitting the individual absorption spectra of the constituents to the measured absorption spectrum of the web. Means for calibrating the reflectance and transmittance measurements and for keeping the sensor viewing windows free of dirt and dust are also disclosed.
Abstract:
A portable analysis spectrometer (10) for field mineral identification is coupled to a microprocessor (11) and memory (12) through a bus (13) and A/D converter (14) to display (16) a spectrum of reflected radiation in a band selected by an adjustable band spectrometer (20) and filter (23). A detector array (21) provides output signals at spaced frequencies within the selected spectrometer band which are simultaneously converted to digital form for display. The spectrum displayed is compared with a collection of spectra for known minerals. That collection is stored in memory and selectively displayed with the measured spectrum, or stored in a separate portfolio. In either case, visual comparison is made. Alternatively, the microprocessor may use an algorithm to make the comparisons in search for the best match of the measured spectrum with one of the stored spectra to identify the mineral in the target area.
Abstract:
A multi-wavelength time-sharing apparatus usable in various different configurations of optical measuring equipment to provide a plurality of time-shared optical channels and including appropriate circuitry. The apparatus employs a turbine-driven filter wheel having a shaft position-encoding arrangement consisting of a hollow shaft portion which is internally illuminated. The hollow shaft portion has two sets of spaced apertures cyclically communicating with respective angularly spaced pairs of externally fixedly mounted phototransistors which are sequentially illuminated as the shaft portion rotates and which produce timing pulses which drive Schmitt triggers, which, in a typical embodiment, in turn produce pulses compatible with a logic circuit employed to decode the phototransistor signals into triggers for driving a 4-channel switched gain equalizer, a dark current clamp, and detector gates. Appropriate selection of the signals enables the instrument to function as a fluorometer or a spectrophotometer.
Abstract:
Characterizing, identifying, or diagnosing the type and/or nature of a sample or a tissue such as an abnormal growth using a Raman spectrum includes analyzing distinct spectral subintervals within the Raman spectrum in two distinct wavelength ranges, such as FP and HW wavelength ranges, to identify a match with one or more reference markers in one or both wavelength ranges; and from the match characterizing, identifying, or diagnosing the type and/or nature of the sample or tissue. FP and HW Raman spectra can be detected or acquired simultaneously using a single diffraction grating.