933 Retroreflectivity Goniometer System

The 933 Retroreflective Workstation measures retroreflection (RA) and the retroreflective color of materials. The 933 contains a 3-axis motorized goniometer that features continuously adjustable β1 (-60° to 60°), β2 (-60° to 60°), and ε (-180° to 180°) angles, as well as a motorized, continuously adjustable α (0.2° to 2°) angle mechanism. The observation angle on the color detector is fixed at 0.33°.

The primary light sensor meets ASTM E1709 requirements with the CIE standard human eye response in conjunction with the CIE illuminant “A” lamp. The photometric filter accurately measures different colors without the need to calculate correction factors. The color detector features a 3-channel RGB sensor used to generate CIE1931 color coordinates.


  • Description
  • Standard Features
  • Specifications

Benchtop four-axis goniometer system for testing sign sheeting and high visibility clothing. Inspection QA test tool for quick testing at multiple measurement geometries.


The user interface features a high-resolution color touch screen. A separate graphics co-processor provides quick, intuitive response as well as clearly rendered text and images for easy viewing of pertinent data.


The unit can be operated as a stand-alone unit, in which case the internal memory has the capacity to store readings and accompanying data for more than 30,000 measurements in non-volatile flash memory. Additionally, the 933 can be controlled over USB via simple ASCII commands to automate multi-measurement situations. USB drivers for Windows, Mac, and Linux are available, as well as sample Windows software utilizing Excel that demonstrates macro control.


  • RA value
  • β1, β2, ε, and α angles
  • CIE1931 x and y coordinates
  • Current date and time
  • Temperature and Humidity
  • A user-entered comment of up to 18 characters
General Specifications
Primary Observation Angle α Automated, variable from 0.2° to 2.0° 
Color Observation Angle 0.33° 
β1 Angle Continuously variable from -60° to 60° 
β2 Angle Continuously variable from -60° to 60° 
ε Angle Continuously variable from -180° to 180° 
Light Source Angular Sub-tense 0.1° 
Primary Receptor Angular Sub-tense 0.1° 
Color Receptor Angular Sub-tense 0.4° 
Measurement Area Approximately 1 inch (2.6cm) in diameter 
Measurement Range, Primary Sensor 0.1 to 10000 cd/m2/lux in 4 electrical auto-gained ranges 
Measurement Range, Color Sensor 10 to 2000 cd/lux/m2 
Data Storage 30,000 measurements via on-board flash memory
Computer Interface USB
Main Detector Silicon photodiode with photopic filter combined with 
light source at CIE Illuminant “A” (2856°K) 
Color Detector RGB detector with photopic filter, calibrated to CIE1931 standard 
Display Interface High Resolution Color Touchscreen 
Comment Field 18-character per measurement
Emergency Stop Button Stops the goniometer instantly 
Door Safety Switch Prevents Goniometer operation unless door is closed 
Power Universal Input, 120-240V 
Operating Temperature 15oC to 30oC (50oF to 104oF) 
Operating Humidity 0 to 95% non-condensing 
Sensors Temperature, Humidity 
Dimensions  22 in. (56 cm) wide; 32.5 in. (83 cm) high; 26 in. (66 cm) deep 



Calibration Standard Annual Calibration Service 
Calibration Certificate 
USB Cable 
Power Cord 

customer service

If you need any help placing or tracking an order please contact us directly at 1-858-279-6044