Before tilt /shift of high position
LTL2000
5 mm profile capability.
Competitor |
| < 0.5 mm profile capabilty |
|
|
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After tilt/shift of high position
LTL2000
5 mm profile capability.
Competitor | < 0.5 mm profile capabilty |
|
Area not measured
Figure 6: The LTL2000S(Q) illuminations/measurement fields ( 5mm profile capabil- ity) compared to a system with identical fields (< 0.5 mm profile capability) clearly shows the advantage of the LTL2000S(Q) for obtaining reliable and reproducible meas- urements on real markings.
Qd Measurement
The Qd part of the LTL2000SQ Retroreflectometer measures the Qd (coefficient of diffuse reflected luminance) parameter. The Qd parameter represents the Lightness of road surfaces and road markings seen by drivers of motor vehicles under daylight conditions or with sta- tionary lighting.
The Qd measurement function of the LTL2000SQ complies with the EN1436 for normal non- glossy road markings with a maximum profile. For measurement on glossy road markings or markings with a profile height exceeding 2 mm please contact DELTA.
The illumination system recommended in EN1436 for obtaining the diffuse illumination for measuring of Qd is an integrating sphere but it is also stated that other illuminations systems can be used if similar results are obtained. The very compact illumination systems in LTL2000SQ is a result of a considerable research effort at DELTA using advanced optical simulation programs. The patent pending illumination system is shown in figure 7. The re- sults obtained with this illumination system is in close agreement with results obtained on Qd measurements using an integrating sphere systems as Qd30 for normal
DELTA | LTL2000S(Q) Retroreflectometer | 15 |