Abstract:
Spectrophotometer intended in particular for the optical analysis of samples in a rotatory analyser. In order to attain the characteristics required of a modern spectrophotometer for clinical chemistry and to attain in particular a high reproducibility of the measurements, the spectrophotometer comprises a flash tube, an stabilizing optical device for device for deriving a light beam having a constant spatial distribution from each flash from the flash tube, a grating monochromator for dispersing the light delivered by the stabilizing device and for delivering a beam of filtered light, an optical element for dividing the filtered beam to produce two beams, the first of which travels through a sample for analysis and the second of which reaches a detector which delivers a reference signal corresponding to the intensity of the second beam, and a second detector placed to receive the beam emerging from the sample.
Abstract:
A tristimulus colorimeter employs a multiplexed dual slope integrator digital voltmeter wherein unknown and reference light beams are compared by sequentially applying unknown and reference electrical signals representative of the two respective light beams to the non-inverting and inverting inputs, respectively, of the integrator amplifier. Moreover, a compensating circuit provides for compensation of the colorimeter output signals with respect to reflectance error encountered in the optics portion of the colorimeter with such compensation being provided as a function of the light intensity from the colorimeter light source.
Abstract:
A double-beam spectrophotometer which can be used for dual-wavelength measurement and provide two substantially equivalent beams and a third beam of a different wavelength which advances along the same path as one of the two beams and alternately therewith. The optical elements employed are so arranged that the beams have a sharply defined, very narrow cross sectional area at the chopper having a number of chopping teeth so that the chopping speed can be increased without decreasing the efficiency in the use of the energy of the output signal of the detector. The cells may be placed at different places most suitable for measurement depending upon the kind and/or concentration of the sample to be measured.
Abstract:
A spectrophotofluorometer capable of selectively performing photometry of one of a plurality of secondary lights such as fluorescence, phosphorescence and the like simultaneously emitted from a specimen due to the exciting light from a light source depending on the life time of the secondary light.
Abstract:
There is disclosed a multiple wavelength infrared spectrometer. It includes an optical chopper and a pendulum-like filter carrier which inserts a plurality of filters sequentially into the radiation beam. Filter changes occur during an opaque period of the chopper and each filter remains in place for a predetermined number of radiation pulses. The radiation passes through the sample and onto a detector which produces an electrical signal. An electronic circuit operates upon the signal so produced to provide an output proportional to sample absorbance.
Abstract:
The present invention relates to optical instruments, such as photometers including spectrophotometers, and relates more particularly to a light-shifting device of light refracting type for receiving a beam of light used in such instruments and shifting it into one or the other of two parallel paths. An optical instrument having a light source, means comprising a diaphragm for directing a collimated beam of light from the light source in a path along an optical axis, light-refracting means disposed in the path for receiving the light beam and shifting the beam from its incident path thereto alternately to each of two offset parallel paths which are parallel to the incident path, and means for supporting, in the offset parallel paths, sample and comparison objects to be scanned by the shifted light beam in those paths.
Abstract:
A spectroradiometer having two detectors and a pair of monochromator channels for measuring the intensity of light emitted from an unknown source. One of the monochromator channels is illuminated with light from a reference source, and a fraction of the resulting monochromatic beam is received by the first detector to produce a reference signal. Another fraction of the monochromatic beam is combined with light from the unknown source by directing the two to opposite sides of a rotating chopper and then alternately through the other monochromator channel to the second detector. The second detector produces successive signals respectively corresponding to the intensity of the light from the unknown source and the intensity of the light from the reference source. The ratio between these signals is multiplicatively combined in an electrical circuit with the reference signal from the first detector, thus providing a measurement of the unknown intensity. In cases in which conventional detectors are employed, certain preferred embodiments of the invention include an additional chopper for the light illuminating the monochromator channels to enable a correction for background or dark signals from the detectors.
Abstract:
A fluorescence radiation detector of the Fraunhofer line discriminator type. A sky telescope and an earth telescope each form radiation beams which are directed to a single optical chopper. The chopper sequentially directs each beam through a single Fabry-Perot filter centered at the Fraunhofer line and a single neutral density filter. The chopped segments are recombined to form a beam containing A, B, C, and D portions in time sequence where: A the direct solar intensity within the continuum; B the direct solar intensity inside the selected Fraunhofer line; C the reflected solar intensity inside the selected Fraunhofer line; and D the reflected solar intensity in the continuum. A single photomultiplier tube with a blocking filter in front receives the beam and produces corresponding sequential electrical pulses which are electronically processed to yield fluorescence (p) from the equation
Abstract:
The beam modulating portion of a spectrophotometer has three beam paths, a first reference beam path, a second reference beam path, and a common sample beam path. The two reference beams are interrupted alternately by respective choppers which operate in synchronism and the sample beam is inserted into the respective interrupted periods of the two reference beams by a reflection mirror to provide two composite signals. The monochrometer portion of this spectrophotometer is a combination of two monochromators of the conventional type each receiving a respective composite signal.
Abstract:
A SPECTROPHOTOMETER WHICH INCLUDES AN OPTICAL SYSTEM ARRANGED BETWEEN THE EXIT SLIT OF A MONOCHROMATOR AND THE SAMPLE CELL SO THAT THE MERIDIONAL AND SAGITTAL IMAGE PLANES OF THE OPTICAL SYSTEM ARE AXIALLY DISPLACED FROM EACH OTHER, THEREBY CAUSING THE BUNDLE OF MONOCHROMATIC LIGHT RAYS TO HAVE A WELL DEFINED, VERY THIN AND SUBSTANTIALY EQUAL CROSS SECTIONAL AREA FOR A LONG DISTANCE ALONG THE OPTICAL AXIS OF THE SYSTEM. WITHIN THIS DISTANCE THE SAMPLE CELL IS PLACED SO THAT THE CELL CAN BE MADE LONGER THAN THE CELLS USED IN THE PRIOR ART SPECTROPHOTOMETERS, WITH THE CROSS SECTIONAL AREA OF THE BUNDLE OF MONOCHROMATIC LIGHT RAYS PASSING THROUGH THE SAMPLE IN THE CELL SUBSTANTIALLY CORRESPONDING TO THE CROSS SECTIONAL AREA OF THE SAMPLE THROUGH THE WHOLE LENGTH OF THE CELL. THIS EN-
SURES EFFICIENT AND ACCURATE MEASUREMENT OF SAMPLES, ESPECIALLY THOSE OF RELATIVELY LOW CONCENTRATIONS.