EULUMDAT

EULUMDAT is a format for the exchange of photometric data of light intensity distribution of light sources. The typical file extension is *. Ldt. The format was developed by Axel Stockmar (Light Consult Inc., Berlin) proposed in 1990 and has since grown in continental Europe the industry standard for the transmission of photometric data. In the UK the format TM14 is preferred in contrast. In the American space parallel to the European standards exist, the format IESNA LM- 63rd

Features

EULUMDAT is a plain ASCII format the data being organized in rows. The characters for the line break follow the convention in DOS and consist of a carriage return (English: carriage return or ) and a line feed (English: line feed or ) in the order < LF >. Programs on operating systems with other conventions such as UNIX or Mac OS must take this into account, so that the cross-platform sharing can work.

As the file format information only on the light intensity, but not the luminance can not be transported contains many properties of a light source therein. Thus, for example Glare ratings only be made ​​on the basis EULUMDAT, if the light sources have a homogeneous radiating surface. However, this is in many of today's lamps, especially for lamps or light-emitting diodes do not. A glare evaluation is not possible.

File Format

  • Point source with symmetry to the vertical axis = 1
  • Line source = 2
  • Point source with a different symmetry = 3 (only line sources Ityp = 2, are divided into longitudinal and transverse direction)
  • No symmetry = 0
  • Symmetry to the vertical axis = 1
  • Symmetry to plane C0 - C180 = 2
  • Symmetry for the C90 -C270 plane = 3
  • Symmetry about the levels C0 - C180 and C90 -C270 = 4
  • If ISYM = 0, then Mc1 = 1 and Mc2 = Mc
  • If ISYM = 1, then Mc1 = 1 and Mc2 = 1
  • If ISYM = 2, then Mc1 = 1 and Mc2 = Mc / 2 1
  • If ISYM = 3, then Mc1 = 3 * Mc / 4 1 and Mc2 = Mc1 Mc / 2
  • If ISYM = 4, then Mc1 = 1 and Mc2 = Mc / 4 1
319322
de