Accession Number : AD0693103

Title :   THE COMPUTATION AND USE OF CONE-TO-ROD RATIO SPECIFICATIONS,

Corporate Author : NAVAL SHIP RESEARCH AND DEVELOPMENT LAB ANNAPOLIS MD

Personal Author(s) : Projector,Theodore H. ; Hardesty,George K. C.

Report Date : SEP 1969

Pagination or Media Count : 79

Abstract : The note summarizes the principles that underlie the concept of a cone-to-rod ratio (CRR) and supports the use of CRR in evaluating the suitability of light for situations where it is necessary to consider the dark adaptation of personnel. It is pointed out that many existing specifications continue to refer to CRR's that are derived from computations based on a now obsolete table of scotopic visual efficiency. The logical use of the Commission International de l'Eclairage (International Commission on Illumination) 1951 standard instead of the old data produces CRR's that are quite different numerically but in many instances can be converted from one basis to the other. Figures are given to illustrate the differences. Computational forms are supplied for the entry of spectroradiometric data from sources or of spectral transmittance data from filters to be used with various blackbody light sources as well as several standard nonblackbody sources. (Author)

Descriptors :   (*VISION, *ADAPTATION(PHYSIOLOGY)), (*LIGHTING EQUIPMENT, HUMAN FACTORS ENGINEERING), RETINA, VISUAL ACUITY, INSTRUMENT DIALS, INSTRUMENT PANELS, ILLUMINATION, SPECTROPHOTOMETERS, RADIOMETERS, OPTICAL FILTERS, ULTRAVIOLET SPECTRA, VISIBLE SPECTRA, BLACKBODY RADIATION, COCKPITS

Subject Categories : Anatomy and Physiology
      Air Condition, Heating, Lighting & Ventilating

Distribution Statement : APPROVED FOR PUBLIC RELEASE