A Measuring Method in A-αand B-βCoordinate System for Useful Luminous Flux of Directional Lamp
Ma Lijia Barbara Ma
Zheng Zhilei
Abstract：Since EU1194 was published in December 2012, the measuring method for useful luminous flux of directional lamp has confused the lighting industry .In this thesis, we will interpret the definition of useful luminous flux and cone angle (ψdefined by author in this thesis ) in EU1194-2012 and α/βangle in CIE121 , analyze the cone angle distribution in A-αsystem and get the useful luminous flux measuring method for directional lamp in A-αand B-βcoordinate system .
Keywords：directional lampuseful luminous fluxA-αand B-βcoordinate systemgoniometrybeam angle
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 21-23,57 )