Optical Instruments

Last change: 09.12.2018

Retroreflectometer for Traffic Signs and Security Clothing


Retroreflective sheetings are found on traffic signs, vehicles, construction site saftey devices, security clothing etc. Compared to road markings these sheetings are renewed less often. Nevertheless they also underlie a fade of color due to thermal stress, ultraviolet impacts, polution and mechanical damages.

For a fast and easy examination of the optical properties (coefficient of retroreflected luminance, RA) of sheetings DELTA developed the RetroSign GRX. With this device fast and simple checks of all kinds of sheetings and colors are possible, without editing types or colors.

RetroSign GRX fulfills the requirements of DIN EN 12899, ASTM E-1709 and ASTM E-2540 for traffic signs as well as of DIN EN 20741 and ASTM E-1809 for security clothing (resolution: 1 decimal place).

State of the art sensor technology enables the RetroSign GRX to measure the retroreflective properties of sheetings with 1, 3 or 7 observation angles at the same time. Colors are recognized and documented in parallel. Also images of the sheetings can be taken during the measurement. All devices are supplied with an illumination angle of +5° (CEN).

By default the systems are supplied with the following angle combinations.

  GRX-1 GRX-3 GRX-7
Trafic Signs 0,33° 0,33°; 0,50°; 1,00° 0,20°; 0,33°; 0,50°; 0,70°; 1,00°; 1,50°; 2,00°
Security clothing 0,20° - -
Number plates - 0,20°; 0,33°; 1,50° -
Materials acc. to DIN EN 12899 - 0,20°; 0,33°; 2,00° 0,20°; 0,33°; 0,50°; 0,70°; 1,00°; 1,50°; 2,00°


Alternatively the RetroSign GRX can also be supplied with a -4° illumination angle according to the ASTM standard. Please contact us, in case you need different angle combinations.

The RetroSign GRX is operated via a 5 inch WVGA color touch display, which can be read properly duing extreme sunshine as well as in the dark.

Factory provided the RetroSign GRX is equipped with all possible hard- and software modules, which can be activated anytime in the future.

This unique scalability enhances operators of the RetroSign GRX to activate modules like the camera or the GPS module whenever they want, in case these features haven´t been activated when the instrument was delivered.


Customers GR1 GR3 Saftey GRX
Landesamt für Straßenbau und Verkehr M-V, Güstrow, Germany       X
Ecolab Deutschland GmbH, Germany       X
ASTS e.K., Hamburg, Germany (3 systems)       X
Erich Utsch AG, Siegen, Germany     X X
NLfSV GB Osnabrueck, Germany (2 systems) X      
PRT GmbH, Austria X      
NLfSV GB Bad Gandersheim, Germany X      
NLfSV GB Hameln, Germany X      
NLfSV GB Stade, Germany X      
Hansestadt Bremen, Germany X      
3M, Neuss, Germany (6 systems) X X X  
NEKS d.o.o., Slovenia   X    
GIO-Lite Europe, Trittau, Germany     X  
AS System, Trittau, Germany     X  


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BASt, Federal Highway Research Institute, retroreflection, RetroSign, Delta Light & Optics, traffic signs, security clothing, lens attachement, DIN EN 12899, ASTM E 1709