Background compensation for spectrometers used in quantitative spectrochemical studies

Claim 1

IN A MULTI-CHANNEL FLAME SPECTROMETER FOR USE IN QUANTITATIVE, SPECTRO-CHEMICAL STUDIES OF A SAMPLE CONTAINING A PLURALITY OF CHEMICAL ELEMENTS AND HAVING A SLIT THROUGH WHICH A BEAM OF HETEROGENEOUS LIGHT RESULTING FROM THE EXCITATION OF THE SAMPLE IS DIRECTED TO A DISPERSING DEVICE WHICH PROVIDES A DISPLAY OF SPECTRAL FREQUENCIES IN A FOCAL CURVE, THE COMBINATION OF AN ISOLATOR LOCATED WITH RESPECT TO SAID DISPLAY TO ISOLATE A CHARACTERISTIC FREQUENCY OF A SELECTED ONE OF THE CHEMICAL ELEMENTS PRESENT IN THE SAMPLE BUT INCLUDING BACKGROUND RADIATIONS AND ESTABLISHING A FIRST SOURCE OF LIGHT ENERGY, AN ISOLATOR LOCATED WITH RESPECT TO SAID DISPLAY IN A ZONE EXCLUSIVE OF FREQUENCIES CHARACTERISTIC OF ANY ELEMENT IN THE SAMPLE AND ESTABLISHING A SECOND SOURCE OF LIGHT ENERGY, RECEIVING MEANS FOR THE LIGHT ENERGY FROM SAID SOURCES AND OPERABLE TO CONVERT SEPARATELY THE LIGHT ENERGY FROM EACH SOURCE TO ELECTRICAL ENERGY AS A MEASURE OF RADIATIONS PRESENT, AND INDICATING MEANS EMPLOYING SAID ELECTRICAL ENERGIES TO EFFECT AN INSTANTANEOUS AND CONTINUOUS READING REPRESENTING THE ISOLATED FREQUENCY OF THE SELECTED ELEMENT LESS THE BACKGROUND RADIATIONS ACTUALLY PRESENT.