Accession Number : ADA194316

Title :   The Electromagnetic Spectrum - The Information Mine.

Descriptive Note : Technical rept.,

Corporate Author : ARIZONA UNIV TUCSON DEPT OF CHEMISTRY

Personal Author(s) : Denton, M B ; Bilhorn, Robert B ; Sweedler, Jonathan V

PDF Url : ADA194316

Report Date : 04 Feb 1988

Pagination or Media Count : 8

Abstract : Optical emission spectroscopic techniques play a wide role in modern chemical analysis. Over the years, these techniques have achieved new realms of sensitivity, selectivity, and accuracy. Early instruments employing photographic emulsion readout have been largely replaced with computer controlled systems. These systems either scan various wavelength regions or, in the case of direct reading spectrometers, contain banks of discrete photomultiplier tubes used to simultaneously observe a limited number of carefully selected wavelengths. This so called progress has, without question, eliminated many laborious and time consuming tasks required to extract quantitative information from photographic emulsion. However, these time savings are costly because of the loss of the fantastic amount of information available when a large range of wavelengths are observed simultaneously. In atomic spectroscopy, most elements have several to hundreds of spectral lines; monitoring only one wavelength can lead to serious errors. Accurate background correction, source and system diagnostics and wavelength selection are often limited or compromised. Even with these significant problems, direct readers generally outperform scanning instruments which suffer from their inherent need to observe each discrete wavelength separately, whether background or analyte line.

Descriptors :   *CHEMICAL ANALYSIS, *EMISSION SPECTROSCOPY, ACCURACY, ATOMIC SPECTROSCOPY, BACKGROUND, COMPUTERS, CONTROL SYSTEMS, CORRECTIONS, DIAGNOSIS(GENERAL), ELECTROMAGNETIC SPECTRA, METHODOLOGY, MINES(ORDNANCE), MONITORING, OPTICS, PHOTOGRAPHIC EMULSIONS, PHOTOMULTIPLIER TUBES, QUANTITATIVE ANALYSIS, READING, REGIONS, SAVINGS, SELECTION, SPECTRAL LINES, SPECTROMETERS, SYSTEMS ANALYSIS, TIME, CHARGE TRANSFER

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE