National Calibration Facility for Retroreflective Traffic Control Materials (2005)

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LIST OF FIGURES Figure 1 – System for specifying and measuring retroreflectors Figure 2 – Conceptual drawing of the CHARM facility Figure 3 – Presented is a schematic of the Strip Lamp Projection System Figure 4 – Shown is the normalized luminous intensity of the strip lamp source over a 45 h period Figure 5 – Shown is the correlated color temperature of the strip lamp source over a 45 h period. Figure 6 – Shown is the sensitivity curves for different materials with respect to CCT. Figure 7 – Shown is the retroreflectance curves used for the CCT sensitivity calculations. Figure 8 – Shown is the uniformity of the source aperture. Figure 9 – Shown is a demonstration of the aperture synthesis procedure. Figure 10 – Shown is the model used in calculating the source aperture uniformity dependence for other systems Figure 11 – Presented is the RL dependence on the source aperture diameter, where the red squares are the beaded material and the blue diamonds are the prismatic material. Figure 12 – Shown is the uniformity of the projection system at the retroreflector aperture surface. Figure 13 – Shown is a demonstration that the sections of the retroreflective device are illuminated with a different set of angles than the center of the device. Figure 14 – Shown is the uniformity of the sphere source projection system at the retroreflector aperture surface. Figure 15 – Shown is a schematic of the goniometer with all the axes labeled. Figure 16 – Shown is a picture of the goniometer. Figure 17 - Shown is a schematic of the goniometer communication system. Figure 18 – Shown is the rotation axis of the goniometer. Figure 19 – Shown is the ball tool mounted in the goniometer. Figure 20 – Shown is the front of the vacuum mount. Figure 21 – Shown is the alignment tool in position with a sample mounted. Figure 22 – Shown is a section of the rail system. Figure 23 – Shown is the theodolite distance minus the magnetic encoder distance. Figure 24 – Shown is the change in RL dependent on the illumination distance. Figure 25 – Shown is the vertical deviation of the sample holder compared to the illumination axis. vii

Figure 26 – Shown is the horizontal deviation of the samples holder compared to the illumination axis. Figure 27 – Presented is a schematic of the photometric detection system. Figure 28 – Presented is a schematic of the observation angle positioner. Figure 29 – Shown is the spectral responsivity of the photometric detection system (solid) versus the CIE V(λ) function (dotted). The dashed line at the top shows the difference between the two curves multiplied by 10. Figure 30 – Shown is the change in RL dependent on the 2 m axis positioning. Figure 31 – Shown is the change in RL dependent on the rotary stage positioning. Figure 32 – Shown is the change in RL dependent on the 20 cm axis positioning. Figure 33 – Presented is the response uniformity of the photometric detection system. Figure 34 – Sample CHARM and STARR spectra for BCRA tiles. Figure 35 – Shown is three spectra using the corrected diode array system. Figure 36 – Aperture holders with large and small apertures Figure 37 – Alignment of rotation angle Figure 38 – Shown is the change in RL dependent on the observation angle for a white encapsulated lens signage material. Figure 39 – Shown is the change in RL dependent on the first entrance angle component for a white encapsulated lens signage material. Figure 40 – Shown is the change in RL dependent on the second entrance angle component for a white encapsulated lens signage material. Figure 41 – Shown is the change in RL dependent on the rotation angle for a white encapsulated lens signage material. Figure 42 – Shown is the set of retroreflective samples used in the MAP service originally. Figure 43 – Shown is the filter set used in the original MAP service. Figure B-1 – Orientation angle uncertainty dependence viii