Retroreflectometers

RoadVista 922 Handhled Retroreflectometer

RoadVista 922 Handhled Retroreflectometer

For over three decades RoadVista has set the standard in retroreflectometer accuracy, reliability and usability

 

RoadVista Retroreflectometers for Highway Safety

Laserlux G7 Mobile Retroreflectometer Quickly mounts to almost any vehicle, records up to 400 measurements per second and features software that works on any device with a Wifi connection and web browser.

922 Handheld Retroreflectometer: Ensures a cost effective, safe, absolute means of meeting the minimum retroreflectivity requirements for traffic signs. Captures measurements for any type of retroreflective material and measures to ensure compliance with MUTCD minimum retroreflectivity requirements.

StripeMaster 2 Touch Handheld Retroreflectometer: Provides quick and easy measurement of pavement markings per ASTM E1710 and EN 1436 utilizing the CEN 30-meter geometry. Provides accurate measurement on wet (per ASTM recovery and continuous wetting methods) or dry surfaces.

932 Handheld Retroreflectometer: Patented design to fully characterize the retroreflection (RA) and retroreflected night-time (CIE1931xy) color of road signs, high visibility safety clothing and other materials.

933 Retroreflectivity Workstation: Benchtop four-axis goniometer system for testing sign sheeting and high visibility clothing. Inspection Q&A test tool for quick testing at multiple measurement geometries.

940D Photometric Range System: Ultimate platform for photometric testing of retroreflective materials. Provides complete and accurate retroreflection measurements.

1200K Handheld Retroreflectometer: Quickly and accurately measures all types of raised pavement markers, including RRPM’s (Cat Eyes)

 

Practical Applications of Retroreflectometers

Laboratory measurement of retroreflective materials is accomplished using tightly controlled procedures. These procedures are defined and controlled by the American Society for Testing of Materials (ASTM). The ASTM procedures for laboratory measurements require the use of a tungsten lamp operated at a correlated color temperature of 2855.6 degrees Kelvin. The spectral power distribution of a tungsten lamp operated at this color temperature approaches the ideal CIE (the international standards generating organization for illumination and color) Illuminant A, which is an internationally agreed upon standard type of illumination used for comparison and specification of colors. The photoreceptor used to measure the illuminated retroreflective surfaces must match the CIE 1931 human eye response function within a tolerance of 3% defined by the f1′ (f-one-prime) analysis method given in CIE publication 69. The CIE 1931 human eye response function is also called the photopic response, photometric response function or the Y-bar function. This level of precision in the measurement instruments yields a precision and bias of about 6% between well-maintained and well-staffed laboratories.

It is not practical to apply these very rigorous standards in the field. ASTM has developed standard procedures that provide for the use of portable instrumentation for measurement of retroreflective materials in the field. These standard procedures allow the use of illumination sources quite different than those used in the laboratory. The procedures allow compensating the detector response by the amount the light source deviates from 2855.6 degrees Kelvin. Field measurements and laboratory measurements taken over many years have shown that the combination of the spectral power distribution of a light source and the detector spectral sensitivity must match the combination of the CIE Illuminant and photometric response functions. Filters can be used to compensate for temperature differences and to provide the required match to the CIE photometric response function.

For pavement markings, the Federal Highway Administration has adopted the 30-meter observation distance geometry used in Europe, defined in ASTM E1710-95. It represents what a driver in an average height U.S. automobile would see during inclement weather conditions at night. ASTM has recently adopted E1710, which establishes the parameters for 30-meter geometry retroreflectometers.