Punched Cards as Position Indicators for Spectrographic Plates

  • J. M. McCrea


Rapid location of the significant regions on spectrographic plates by use of templates or position indicators can speed up plate measurements considerably. Punch cards for computer use provide a basic grid of 960 positions over a 7.0-in. ×2.9-in. area, and in several designs the 12 rows and 80 columns are legibly numbered. Holes in a punch card serve not only to indicate position, but can also be used as windows for photometric measurements if the card is used as a mask directly on the uncoated side of the plate.




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Copyright information

© Plenum Press, New York 1971

Authors and Affiliations

  • J. M. McCrea
    • 1
  1. 1.Applied Research LaboratoryUnited States Steel CorporationMonroevilleUSA

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