Source for Retroreflectance Meter
HunterLab has never built instrumentation for retro-reflectance, a specialized field typically applied to highway signage and safety clothing, but here are three manufacturers that do:
San Diego, CA 92123 USA
RoadVista makes retroreflectance instruments for highway markings and signage that conform to EN 1436 and ASTM E1710
RoadVista has a publication "Guide to Retroreflective Measurement Principles for Highway Signs and Markings" at http://www.roadvista.com/guideSummary.shtml which is useful in understanding retro-reflectance of highway signage.
Zehntner Testing Instruments GmbH
+41 (61) 953 05 50
Zehntner Instruments make a variety of gloss meters, reflectometers and retro-reflectometers specifically for highway road markings, including EN 1436.
US Distributor for Zehntner Testing Instruments:
Avian Technologies LLC
Sunapee, NH 03782 USA
+45 (72) 19 40 00
Delta has a variety of retro-reflectometers, both road material measurement units and a gun for highway signs all of which conform to various DIN, ASTM and CEN specifications. Also has a 0/d sphere instrument for daylight visibility (luminous coefficient) of road markings that conforms to EN 1436 Road marking materials - Road marking performance for road users.
US Distributor for Delta:
Thomasville, NC 27630 USA