The provision of reliable and accurate photometric data is a basic requirement for any lighting engineer in order to design a good lighting scheme. This European Standard has the task of creating a common basis for European lighting practices so that the photometric data of a luminaire can be prepared and compared on the basis of the same principles in different measurement laboratories across Europe. It specifies general principles for the measurement of basic photometric data for lighting application purposes. Furthermore, it establishes the measurement criteria needed for the standardisation of basic photometric data and specifies details of the CEN file format for electronic data transfer. This standard is a guide to procedures referring where necessary to the relevant CIE, ISO and CEN publications. The committee responsible for this standard is NA 058-00-03 AA "Photometrie" ("Photometry") at DIN.