LTL3000 User Manual / June 2020
8
DELTA
LTL3000 introduction
The LTL3000 retroreflectometer is a portable field instrument intended for measuring the retroreflection and
reflection properties of road markings.
LTL3000 measures the RL value (coefficient of retroreflected luminance at night) and the Qd value (day light
visibility). RL is a measure of the lightness of the road marking as seen by drivers of motorized vehicles in
car headlight illumination. The road is illuminated at an angle of 1.24°. The illumination for Qd is diffuse. The
reflected light for both RL and Qd is measured at an angle of 2.29°, which corresponds, to an observation
distance
of 30 meters. This is relevant for a motorist’s viewing situation under normal conditions. Further
information on measuring principles and standards can be found on
https://roadsensors.madebydelta.com/
LTL3000 measures RL (nighttime visibility) and Qd (daytime visibility) under dry and wet conditions. LTL3000
measures RL from 0 to 4000 mcd·m
-2
·lx
-1
and Qd from 0 to 318 mcd·m
-2
·lx
-1
. LTL3000 can in addition
measure nighttime chromaticity coordinates (x,y).
LTL3000 has automatic ambient light compensation. Daylight and other outside light sources will not affect
the accuracy of the measurements.
Overview of the LTL3000
The LTL3000 retroreflectometer is easy to operate and requires a minimum of instructions.
The measurement results are presented on the instrument
’s touch screen. Each measurement can be linked
to a user/operator name and a series name.
The instrument provides a warning message or sound in case of unreliable measurement.
The majority of action buttons on the LTL3000 are accessible via the touch screen. The physical buttons and
features on the instrument are shown below.
Front and side of the LTL3000:
