Inter-Laboratory Comparison of Luminous Intensity Distribution and Total Luminous Flux Measurements with Far Field and Near Field Goniophotometry

In order to be recognized as a competent testing andcalibration laboratory, metrology laboratories who aim to obtainan accreditation for specific tests need to fulfill a number ofgeneral requirements as stipulated in the International StandardISO/IEC17025. One way to assure the quality of testing is toparticipate in proficiency testing programs or to conduct interlaboratorycomparisons. In this paper, luminous intensitydistribution measurements of three LED lamps, performed intwo metrology laboratories according to the CIE and IESNAstandard guidelines, are presented and compared. Significantdifferences are found for LID results of a directional lamp, due tohigh-dynamic range issues being observed in the near-fieldgoniophotometer. It is also detected that the correlated colortemperature influences the illuminance measurement of thephotometer in the goniophotometer.

Publication year:2014