Apparatus for spectrochemical analysis by the internal standard method

Claim 1

APPARATUS FOR SPECTROSCOPIC ANALYSIS WHICH COMPRISES FIRST RADIATION SOURCE MEANS ADAPTED TO EMIT FIRST WAVELENGTH RADIATION; SECOND RADIATION SOURCE MEANS ADAPTED TO EMIT SECOND WAVELENGTH RADIATION; MEANS FOR COMBINING RADIATION FROM SAID FIRST AND SECOND SOURCE MEANS TO PROVIDE A COMBINED BEAM CONTAINING SAID FIRST AND SECOND WAVELENGTHS; MEANS FOR PERIODICALLY CHOPPING SAID COMBINED BEAM; BEAM SPLITTING MEANS IN THE COMBINED BEAM TO PROVIDE SIMILAR REFERENCE AND SAMPLE BEAMS; MEANS FOR PASSING THE SAMPLE BEAM THROUGH A SAMPLE AREA; MEANS ADAPTED TO FORM A SLIT IMAGE OF THE SAMPLE AND REFERENCE BEAMS, ONE END OF THE SLIT IMAGE BEING FORMED BY THE SAMPLE BEAM, THE OTHER END BEING FORMED BY THE REFERENCE BEAM; SPLIT LITTROW BICHROMATOR MEANS ADAPTED TO RECEIVE AT ITS ENTRANCE SLIT THE RADIATION FROM SAID SLIT IMAGE AND PRODUCE AT ITS EXIT SLIT AN IMAGE CONTAINING ONLY FIRST AND SECOND WAVELENGTH RADIATION; MEANS ADAPTED TO RECEIVE THE BEAM OF RADIATION EMANATING FROM SAID EXIT SLIT AND FORM THEREIN THE IMAGE OF SAID SPLIT LITTROW MIRROR AT A FIRST LOCATION AND THE IMAGE OF THE BICHROMATOR ENTRANCE SLIT AT A SECOND LOCATION; FIRST REFLECTING MEANS AT SAID FIRST LOCATION ADAPTED TO RECEIVE THE IMAGE OF ONE PORTION OF SAID SPLIT LITTROW MIRROR AND DIRECT FIRST WAVELENGTH RADIATION IN A FIRST DIRECTION; SECOND REFLECTING MEANS AT SAID FIRST LOCATION ADAPTED TO RECEIVE THE IMAGE OF THE OTHER PORTION OF SAID SPLIT LITTROW MIRROR AND DIRECT SECOND WAVELENGTH RADIATION IN A SECOND DIRECTION; FIRST RADIATION DIVIDER MEANS IN SAID FIRST WAVELENGTH RADIATION AT SAID SECOND LOCATION TO DIVIDE THE FIRST WAVELENGTH BEAM INTO SAMPLE AND REFERENCE PORTIONS; SECOND RADIATION DIVIDER MEANS IN SAID SECOND WAVELENGTH RADIATION AT SAID SECOND LOCATION TO DIVIDE THE SECOND WAVELENGTH BEAM INTO SAMPLE AND REFERENCE PORTIONS; AND MEANS ADAPTED TO MEASURE THE INTENSITY OF THE INTERMITTENT RADIATION OF THE REFERENCE AND SAMPLE PORTION OF EACH OF THE FIRST AND SECOND WAVELENGTH BEAMS.