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Interference filter transmission wavelength scanning photometer

  • US 20020190211A1
  • Filed: 10/26/2001
  • Published: 12/19/2002
  • Est. Priority Date: 02/28/2000
  • Status: Active Grant
First Claim
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1. An interference filter transmission wavelength scanning photometer for determining concentration of an interesting component in a sample without interfering of the coexistent components by applying the light absorption of the interesting component comprising:

  • a light source, an interference filter which has means scanning transmission wavelength periodically, an infrared sensor and a zero cross detector;

    said photometer having functions to determine concentration of an interesting component in a sample by operations comprising the steps of;

    deciding range of scanning the transmission wavelength of said interference filter, so that center of small change of wavelength induced by scanning the transmission wavelength periodically is equal to an absorption wavelength of said interesting component;

    detecting intensity of light beam from said light source as an electric signal by said infrared sensor in which light beam is put, after transmitting through said interference filter and transmitting or reflecting on said sample put front or rear of said interference filter;

    obtaining a full period T (time for every other zero cross point of the AC component) and half period T1 (time for every zero cross point of the AC component) which said zero cross detector takes out of the AC component of said electric signal;

    determining concentration of said interesting component by calculating a ratio (T−

    2T1)/T.

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