VS - Lighting Systems - Lighting - 998542

11.1.1. Xenon, a discharge lamp tuned to automotive applications Automotive HIDs can be called “Xenon headlamps”, but they are actually metal-halide lamps that contain Xenon gas.

The regulation ECE R99 specifies Xenon colour tolerance on the chromaticity grid, the colour objective is x = 0.375 and y = 0.375. The tolerances on the graph correspond to a range between 4000 K and 5000 K; when comparing the colour temperature of Tungsten-Halogen lamps, it varies from 3000 K to 3550 K. Lower colour-temperatures exhibit a higher red rendering and higher temperatures exhibit a blue rendering.

The right spectral distribution

One of the most important parameters to take into account in selecting a light source is the spectral distribution (or wavelength profile) emitted by the source. The light spectrum produced by the Xenon lamps is optimized to maximize human eye visual perception.

Halogen and Xenon positioning CIE 1931 x,y chromaticity diagram

0.46

MAX.

MAX.

XENON

2700K

0.44

3000K

507 nm

555 nm

100

3500K

0.42

4000K

0.40

4500K

80

5000K

Y

0.38

5700K

0.36

6500K

60

HALOGEN

0.34

0.32

40

0.30

20

0.28 0.28 0.30 0.26 0.32 0.34 0.36 0.38 0.40 0.42 0.44 0.46 0.48 0.50 0.52

Relative emission and sensitivity

X

0

400

500

600

700

800

450

550

650

750

Colour wavelength (nm)

Xenon spectral power distribution Human vision photopic sensitivity (day light adapted) Human vision scotopic sensitivity (night adapted)

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