Delta RetroSign GRX-1, User Manual

Page: 9 / 80

RetroSign GRX User Manual / December 2017
9
DELTA
SECTION 1: Introduction
GRX usage
RetroSign GRX retroreflectometer is a portable field instrument for on-site inspection and quality
control of all types of road traffic signs, high visibility clothing, conspicuity tapes, and license plates,
that are illuminated by vehicle headlights in darkness e.g. at night time or in road tunnels.
What does GRX measure?
RetroSign GRX measures the value R
A
(coefficient of retroreflected luminance at night). R
A
is a
measure that indicates the visibility of the road traffic signs, high visibility clothing, conspicuity tapes,
and license plates as seen by drivers of motorized vehicles in headlight illumination.
Models
RetroSign GRX is a retroreflectometer with LED source technology. It measures retroreflectivity at up
to 7 observation angles.
The retroreflectometer is based on point aperture geometry comparable to laboratory readings
reflecting real-world driving conditions and allows detection of incorrect sheeting application.
RetroSign GRX combines CEN and ASTM geometries in one instrument and is available in three
base models:
•
GRX-1 : one entrance/illumination and 1 observation angle
•
GRX-3 : one entrance/Illumination and 3 observation angles
•
GRX-7 : one entrance/illumination and 7 observation angles
When using ASTM geometry the sign is illuminated at an entrance angle of -4º, whereas CEN
geometry means that the sign is illuminated at an entrance angle of +5º. DELTA can supply additional
entrance/illumination angles of +10º, +20º, +30º, +40º
,
and +45º if required. The entrance/illumination
angles are determined by the angle adapter mounted at the front of the GRX.
The exact model, with 1, 3, or, 7 observation angles, depends on the needs of the user. The
observation angles available are: 0.2º, 0.33º, 0.5º, 0.7º, 1.0º, 1.5º, and 2.0º.
Depending on the chosen GRX model and the entrance/illumination angle(s) acquired, the instrument
will be able to meet any angle combination stated in relevant European and US standards like EN
12899, ASTM E 1709, and ASTM E 2540 for road traffic signs, and EN 20471, ASTM 1809 for high
visibility clothing.
R
A
is an important factor in the on-site quality control of road traffic signs.