Check the full article at Intertraffic World magazine: http://journal-download.co.uk/digitalmagazines/ITW/ITW01NOV2019/page_173.html
The MINI Vertical is an up to four angle retroreflectometer designed to accurately measure the retroreflection RA of road signs, safety clothing and other
The innovative optical system can measure up to 4 (four) simultaneous observation angles. The entrance angle (β) can be fixed ( −4° / +5° ) or it can be
continuously adjusted by the operator. The combination of adjustable entrance angle with the exclusive quadruple simultaneous observation angles allows precise determination of retroreflection according ISO 20471 and also to all international standards.