Samenvatting
A portable reflectance measuring system suitable for in situ measurement of road signs, pavement markers and road stripes has been constructed. The reflectometer has adequate sensitivity to allow measurements of road stripes at grazing incidence and to permit measurements to be made from off-the-road locations, thus avoiding obstructing traffic or exposing the operating personnel to unnecessary hazards. The use of phase-lock detection techniques to eliminate background radiation allows measurements to be made on a sun-lit target. The instrument's spectral response simulates the human photopic response when viewing under a 2856K (CIE standard source A) lamp as required by federal specification LS-300A.