REFLECTIVITY INSTRUMENTATION DESIGN

A reflectometer has been constructed and used during both daylight and night hours to make field reflectivity measurement of highway signs. The reflectometer operation was made independent of ambient light by using a mechanical chopper to modulate an internal light beam, which is directed toward a sign. A human eye corrected light sensor collects the modulated light reflected from a two degree spot on the sign, and the receiver measures the average value of resulting amplified A.C. voltage component. This represents relative reflectance. This report discusses the design considerations, and alternate approaches considered, the prototype and the final instrument. Field measurements are discussed, and possible uses of this and similar instruments are briefly commented on.

• Supplemental Notes:
  • Prepared in cooperation with Louisiana Dept. of Highways, Baton Rouge.
• Corporate Authors:

  Louisiana Tech University, Ruston

  Division of Engineering Research
  Ruston, LA  United States  71272

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590

  Louisiana Department of Highways

  P.O. Box 44245, Capitol Station
  Baton Rouge, LA  United States  70804
• Authors:
  • Williams, T
• Publication Date: 1974-12

Media Info

• Pagination: 76 p.

Subject/Index Terms

• TRT Terms: Daylight; Design; Field tests; Highways; Instrumentation; Measuring instruments; Navigation lights; Night; Optical instruments; Prototypes; Reflectivity; Reflectometers; Reflectorized materials; Symbols; Traffic safety; Traffic signs; Visibility; Visual perception
• Uncontrolled Terms: Design criteria; Field measurements; Reflectance
• Old TRIS Terms: Light signals
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; Materials; Safety and Human Factors;

Filing Info

• Accession Number: 00133102
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: Final Rpt.
• Files: NTIS, TRIS, USDOT, STATEDOT
• Created Date: Jun 23 1976 12:00AM