If you are experiencing problems downloading PDF or HTML fulltext, our helpdesk recommend clearing your browser cache and trying again. If you need help in clearing your cache, please click here . Still need help? Email firstname.lastname@example.org
A minicomputer-based, semiquantitative, emission spectrographic system was designed to perform survey analyses (64 elements per sample), on a wide variety of geologic materials rapidly (9 s per determination). The system can analyze as many as 40 000 samples per year, while maintaining
long-term consistency of results, and can provide archival storage capability (photoplate, microfiche, data bank). The minicomputer's partitioned memory allows simultaneous execution of programs to acquire 92 000 sequential, digitized, transmittance-readings per spectrum from a precision scanning
microphotometer in 70 s, and to reduce these data to the peak and background transmittances, the location, and a profile code of as many as 500 analytical lines. The plate emulsion is calibrated in 10 equal segments between 2300 and 4700 Å. Intensities and preliminary concentrations
based on prestored analytical curve coefficients are calculated for each line. Corrections for spectral interferences are made, and final results are selected according to a predetermined priority scheme. A report form for every 10 samples is printed within 5 min after a plate is recorded.
All the preliminary data are stored on magnetic tape for production of microfiche within 24 h. Spectra on a second plate can be scanned while analysis of the first plate is being performed.
United States Geological Survey, 957 National Center, Reston, Virginia 22092
Publication date: November 1, 1979
More about this publication?
The Society publishes the internationally recognized, peer reviewed journal, Applied Spectroscopy, which is available both in print and online. Subscriptions are included with membership or can be purchased by institutional or corporate organizations. Abstracts may be viewed free of charge. Previously published as Bulletin (Society for Applied Spectroscopy)