SECTION 2
GENERAL INFORMATION
Rl Measurement
The Rl part of the LTL2000S(Q) Retroreflectometer measures the Rl (coefficient of retro re- flected luminance) parameter. The Rl parameter represents the brightness of the road mark- ings seen by drivers of motor vehicles by headlight illumination.
The illumination angle is 1.24° and the observation angle is 2.29°simulating a drivers view- ing distance of 30 metres at an eye height of 1.2 metres. The observation area is app. 45 mm. x 200 mm.
The optical specification complies with EN1436. The spectral sensitivity is eye matched us- ing SMART optical filter designed and produced by DELTA. The functional layout of the LTL2000S(Q) Rl optical system is shown in figure 3 below.
A very efficient electronic stray light compensation eliminates false signals from daylight.
102 | 101 |
104 | 103 |
106105
101 Light source
102 Receiver and spectral matching filter
103 Illumination aperture stop
104 Observation aperture stop
105 Illumination beam
106 Observation beam
107 Collimating lens
108Mirror
109Beam splitter
110Road marking surface
111Illumination field
112Observation field
107
108 | 109 | 110 | 112 | 111 |
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Figure 3: LTL2000S(Q) RL optical system layout
DELTA | LTL2000S(Q) Retroreflectometer | 11 |
