EULUMDAT File Format Specification

Proposal for a Data Format for Exchange of Luminaire Data (Interior, Exterior, and/or Road Lighting Luminaires) Under the Operating Systems MS-DOS 2.x/3.xx Under Condition of Unequivocal Coordination Between Luminaire and Data Set

Item

Designation

Number of Characters

1

Company identification/data bank/version/format identification max.

Max. 78

2

Type indicator Ityp (1 - point source with symmetry about the vertical axis; 2 - linear luminaire; 3 - point source with any other symmetry) [See Note 1]

1

3

Symmetry indicator Isym (0 - no symmetry; 1 - symmetry about the vertical axis; 2- symmetry to plane C0-C180; 3- symmetry to plane C90-C270; 4- symmetry to plane C0-C180 and to plane C90-C270)

1

4

Number Mc of C-planes between 0 and 360 degrees (usually 24 for interior, 36 for road lighting luminaires)

2

5

Distance Dc between C-planes (Dc = 0 for non-equidistantly available C-planes)

5

6

Number Ng of luminous intensities in each C-plane (usually 19 or 37)

2

7

Distance Dg between luminous intensities per C-plane (Dg = 0 for non-equidistantly available luminous intensities in C-planes)

5

8

Measurement report number

Max. 78

9

Luminaire name

Max. 78

10

Luminaire number

Max. 78

11

File name

8

12

Date/user

Max. 78

13

Length/diameter of luminaire (mm)

4

14

Width of luminaire b (mm) (b = 0 for circular luminaire)

4

15

Height of luminaire (mm)

4

16

Length/diameter of luminous area (mm)

4

17

Width of luminous area b1 (mm) (b1 = 0 for circular luminous area of luminaire)

4

18

Height of luminous area C0-plane (mm)

4

19

Height of luminous area C90-plane (mm)

4

20

Height of luminous area C180-plane (mm)

4

21

Height of luminous area C270-plane (mm)

4

22

Downward flux fraction DFF (%)

4

23

Light output ratio luminaire LORL (%)

4

24

Conversion factor for luminous intensities (depending on measurement)

6

25

Tilt of luminaire during measurement (road lighting luminaires)

6

26

Number n of standard sets of lamps (optional, also extendable on company-specific basis)

4

26a

Number of lamps

n * 4

26b

Type of lamps

n * 24

26c

Total luminous flux of lamps (lumens)

n * 12

26d

Color appearance / color temperature of lamps

n * 16

26e

Color rendering group / color rendering index

n * 6

26f

Wattage including ballast (watts)

n * 8

27

Direct ratios DR for room indices k = 0.6 ... 5 (for determination of luminaire numbers according to utilization factor method)

10 * 7

28

Angles C (beginning with 0 degrees)

Mc * 6

29

Angles G (beginning with 0 degrees)

Ng * 6

30

Luminous intensity distribution (candela / 1000 lumens) [See Note 2]

(Mc2-Mc1+1) * Ng * 6

NOTES

1. Only linear luminaires (Ityp = 2) are being subdivided in longitudinal and transverse directions.

2. The parameters Mc1 and Mc2 for the luminous intensity distribution are determined by:

Isym

Mc1

Mc2

0

1

Mc

1

1

1

2

1

Mc / 2 + 1

3

3 * Mc / 4 + 1

Mc1 + Mc / 2

4

1

Mc / 4 + 1

3. Each field is an ASCII string that is terminated with an MS-DOS <CR><LF> pair.

EULUMDAT and Absolute Photometry

Release:            August 20, 2009

This document describes how to generate and interpret an EULUMDAT file containing absolute photometric data.

Without any changes to the EULUMDAT file format specification, an EULUMDAT file representing absolute photometry can be interpreted as:

Item

Designation

Absolute Photometry Value

Notes

26

Number n of standard sets of lamps

1

1

26a

Number of lamps

–n (number of light emitters)

2

26b

Type of lamps

<Unchanged>

3

26c

Total luminous flux of lamps (lumens)

Luminous flux (lm) of luminaire

4

 

 

 

30

Luminous intensity distribution (cd/klm)

<Unchanged>

5

NOTES

1.   Field 26. There can be only one standard set of lamps for absolute photometry, and the value is fixed at 1.

2.   Field 26a. While the number of lamps ‘n’ is meaningless for absolute photometry, it may still be useful to indicate the number of light emitters, such as the number of LEDs. The value is therefore retained, but its sign is negative to indicate absolute photometry.

3.   Field 26b. Type of lamp is just informative. It could be for example the ILCO OS code for a reflector lamp, or the manufacturer’s name for a type of LED.

4.   Field 26c. In accordance with the principles of absolute photometry, this field reports the measured luminous flux of the luminaire rather than the total manufacturer’s rated lumens of the lamps.

An advantage of this interpretation for the luminaire manufacturer is that the reported luminous flux can be measured with for example an integrating sphere rather than a goniophotometer. This makes it possible to measure one luminaire with a goniophotometer to determine its luminous intensity distribution, and then measure multiple identical luminaires to obtain an average total luminous flux value.

5.   Field 30. All values are stated in candela per kilolumen (cd/klm). The advantage is that there is no change to the existing format.

This interpretation is fully compatible with existing EULUMDAT photometric data files, and also with existing lighting design software programs as long as they do not perform range checking on field 26a. (This is unlikely, as the number of lamps is not required when interpreting the luminous flux distribution of a luminaire.)

Implementation

Given that no changes are required to the EULUMDAT file format specification, support for absolute photometry can be provided immediately. Responsibilities for the various parties include:

1.      Photometric Testing Laboratories

+        Use –n in field 26a to designate absolute photometric data reports. (This is a convention only.)

2.      Luminaire Manufacturers

+        Request EULUMDAT files with –n in field 26a for products requiring absolute photometry (primarily for solid-state lighting products, but also for lamps and luminaires with non-removable lamps).

3.      Lighting Design Software Manufacturers

+        Modify future version of their products to indicate EULUMDAT files with absolute photometric data.

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