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US 4,057,734 AGranted
Spectroscopic apparatus with balanced dual detectors
AssigneeBarringer Research Limited
InventorAnthony Rene Barringer
Life of this patent
Estimating the term…
Abstract
A spectrometer having two photoelectric channels the outputs of which are compared in order to measure gas or liquid concentrations, and means for automatically balancing the photoelectric channels immediately prior to each successive measurement, said means including a reference source of radiation which is utilized for balancing both photoelectric channels, so that when a measurement of the gas or liquid is being made, both photoelectric channels as nearly as possible are effectively balanced.
Claims15
Spectroscopic apparatus for analyzing spectra of predetermined wavelengths, comprising:
- a. means for receiving radiation containing the spectra to be measured from a first source and for forming the radiation into a first beam,
- b. first and second photoelectric channels respectively comprising first and second photodetectors for converting radiation incident upon said photodetectors into electric currents and electronic circuit means connected to said first and second photodetectors for producing first and second signals which respectively are proportional in amplitude to the intensity of the radiation shining on said first and second photodetectors, said first photodetector being positioned to receive a first portion of radiation in said beam, said first portion constituting a measuring beam, and said second photodetector being positioned to receive a second portion of radiation in said beam, said second portion constituting a reference beam, said measuring beam containing the spectra to be measured and said reference beam containing spectral components of wavelengths such that comparison of the intensity of the measuring and reference beams provides a measure of the intensity of said spectra,
- c. means optically coupled to a reference source of radiation for producing a second beam of radiation,
- d. means operable cyclically for sequentially exposing said first and second photodetectors simultaneously to radiation in said first beam, and exposing said first and second photodetectors simultaneously to radiation in said second beam, and
- e. means for comparing the levels of said first and second signals when said first and second photodetectors are exposed to radiation from said first source including means responsive to the respective levels of said first and second signals when said first and second photodetectors are exposed to radiation in said second beam for compensating for the effect of any unbalance between said first and second photoelectric channels.
2 more elements
Dependencies are inferred from the claim text.