A minicomputer-based emission spectrographic analysis system: the program
Explore the source record for details and available documents.
Open-File Report↗
Geology topics
Catharine P. Thomas
Publications and source records attributed to Catharine P. Thomas.
An integrated-intensity method for emission spectrographic computer analysis
An integrated-intensity method has been devised to improve the computer analysis of data by emission spectrography. The area of the intensity profile of a spectral line is approximated by a rectangle whose height is related to the intensity difference between the peak and background of the line and whose width is measured at a fixed transmittance below the apex of the line. The method is illustrated by the determination of strontium in the presence of greater than 10 percent calcium. The Sr 3380.711-A line, which is unaffected by calcium and which has a linear analytical curve extending from 100-3,000 ppm, has been used to determine strontium in 18 standard reference rocks covering a wide range of geologic materials. Both the accuracy and the precision of the determinations were well within the accepted range for a semiquantitative procedure.
Journal of Research of the U.S. Geological Survey↗