Periodically alternating path and alternating wavelength bridges

Details Periodically alternating path and alternating wavelength bridges Periodically alternating path and alternating wavelength bridges

1993-12-03

1995-01-10

Dzierzynski, Paul M.

Radiant energy

Invisible radiant energy responsive electric signalling

Infrared responsive

25033913, 250345, G01N 2161

Patent

active

053810104

ABSTRACT:
An apparatus for ultrasensitive detection of low concentrations of constituents using a broad band LED source is described. The apparatus provides enhanced resolution by synchronously detecting an imbalance between two analog signals due to absorption in a measurement cell at a wavelength of interest. Elements are provided to balance the signals in the absence of absorption to provide a reference point for concentration calculations. In accordance with several embodiments of the present invention, a time alternating signal for synchronous detection is achieved by combining signals from each of two alternating paths, only one of which travels through the measurement cell and which may have absorption. If there is absorption in the measurement cell, then the signal created by combining the alternating paths will exhibit residual modulation at the path alternation rate. In accordance with another embodiment of the present invention, a time alternating signal is achieved by combining signals from each of two alternating ultranarrow wavelength channels, each of which travels through the measurement cell but only one of which is on an absorption line of a constituent believed to be in the measurement cell, into a single photosensitive device. If there is absorption in the measurement cell, then the signal from the photosensitive device formed by combining the alternating wavelength channels will exhibit residual modulation at the wavelength channel alternation rate.

REFERENCES:
patent: 3796887 (1974-03-01), Vincent et al.
patent: 3807876 (1974-04-01), Nakahara et al.
patent: 3810696 (1974-05-01), Hutchins, Jr.
patent: 3904880 (1975-09-01), Benz et al.
patent: 3924950 (1975-12-01), Siegler, Jr.
patent: 3968367 (1976-07-01), Berg
patent: 3995960 (1976-12-01), Fletcher et al.
patent: 4118625 (1978-10-01), Underwood
patent: 4136959 (1979-01-01), Honkawa et al.
patent: 4171909 (1979-10-01), Kramer et al.
patent: 4236826 (1980-12-01), Yamanishi
patent: 4241997 (1980-12-01), Chraplyvy
patent: 4305663 (1981-12-01), Perkins et al.
patent: 4455097 (1984-06-01), Ichikawa et al.
patent: 4525627 (1985-06-01), Krempl et al.
patent: 4577105 (1986-03-01), Krempl et al.
patent: 4629322 (1986-12-01), Pollard
patent: 4637730 (1987-01-01), Ponstingl et al.
patent: 4750837 (1988-06-01), Gifford et al.
patent: 4814604 (1989-03-01), Lequime
patent: 4817013 (1989-03-01), Corenman et al.
patent: 4856899 (1989-08-01), Iwaoka et al.
patent: 4899053 (1990-02-01), Lai et al.
patent: 4921351 (1990-05-01), Kohigashi et al.
patent: 5055688 (1991-10-01), Fabinski
patent: 5064283 (1991-11-01), Tober
patent: 5173749 (1992-12-01), Tell et al.
patent: 5185645 (1993-02-01), Sartorius et al.
Article entitled Applications of Single and Multilayer Films, Published in OPTICS, Second Edition, by Eugene Hecht, Adelphi University, Addison-Wesley Publishing Company, pp. 377-378.
Article entitled Near-Infrared Diode Lasers Monitor Molecular Species, by David E. Cooper and Ramon U. Martinelli, Published in Laser Focus World, November 1992 issue, pp. 133-146.
Article entitled Combined Wavelength and Frequency Modulation Spectroscopy: A Novel Diagnostic Tool for Materials Processing, by H. C. Sun, E. A. Whittaker, Y. W. Bae, C. K. Ng, V. Patel, W. H. Tam, S. McGuire, B. Singh, and B. Gallois, published in Applied Optics, 20 Feb. 1993, vol. 32, No. 6, pp. 885-893.

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