Accession Number:

ADA050630

Title:

A Comparison of Inter-Symbol Contrast Ratios for Segmented Digital Readouts.

Descriptive Note:

Final rept. Sep 75-Jun 76,

Corporate Author:

AERONAUTICAL SYSTEMS DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s):

Report Date:

1977-12-01

Pagination or Media Count:

46.0

Abstract:

Twelve subjects viewed a Chicago Miniature segmented digital readout display to compare symbol legibility under two inter-symbol contrast ratio conditions - 41 and 21. Using two test lamps designated A and B, a series of test trials was presented under both conditions randomly intensifying the three horizontal segments of symbol A to determine the effect, if any, on symbol legibility. The stimuli consisted of numerical digits digits 3, 5, and 9 were presented at symbol A and digits 0-9 at symbol B. Performance data were based on subjects digital readout error scores. From evaluation of the performance data, it was concluded that the 41 inter-symbol contrast ratio was significantly better than the 21 condition and that there was no apparent aural effect degrading performance under either condition. Additionally five was significantly misidentified more often--primarily as a nine. This identification error was attributed to insufficient distinguishing cues between the two digits. Author

Subject Categories:

  • Anatomy and Physiology
  • Test Facilities, Equipment and Methods

Distribution Statement:

APPROVED FOR PUBLIC RELEASE