5 factors affecting colour consistency, Iridescence, Ambient temperature – OSRAM DULUX F User Manual

Page 39: Manufacturing tolerances, Dimming, Compact fluorescent lamps osram dulux

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Economical long-life light sources with plug-in bases

Compact Fluorescent Lamps OSRAM DULUX

®

Technical Guide

37

Type

Luminous flux (lm) for light colour

LUMILUX

®

LUMILUX

®

DE LUXE

SPECIAL LIGHT COLOURS

880

SKY-

WHITE

865

Cool

Daylight

840

Cool

White

830

Warm

White

827

INTER-

NA

950

Daylight

940

Cool

White

930

Warm
White

60

Red

66

Green

67

Blue

OSRAM DULUX

®

L 18W SP

1200

1200

OSRAM DULUX

®

L 24W SP

1800

1800

OSRAM DULUX

®

F 18W

1100

1100

1100

OSRAM DULUX

®

F 24W

1705

1705

1705

OSRAM DULUX

®

F 36W

2810

2810

2810

CFL SQUARE

®

16W

1050*

1050

CFL SQUARE

®

28W

2050*

2050

CFL SQUARE

®

38W

2735*

2735

*) Light colour 3500K
1) Also for CONSTANT models
2) Values for an ambient temperature of 25°C, maximum values at ambient temperature of 35°C
3) Also valid for XT models

2.3.5 Factors affecting colour consistency

There are a number of factors that affect colour consistency and the perception of the light colour of
compact fluorescent lamps.

Iridescence

Iridescence is a property of some anodised reflector finishes which results in a „rainbow“ effect
when use in conjunction with tri-chrome phosphors. Since all OSRAM DULUX

®

lamps contain tri-

chrome phosphors, this effect caused by the reflector may be wrongly ascribed to the lamps as
„different light colours“.

Ambient temperature

The light colour of tri-chrome phosphors changes slightly as the ambient temperature changes
because of the relationship between luminous flux and temperature. This is apparent in applications
in which, say, open ceiling light fittings are installed close to air-condition outlets. In such cases, the
light colour may be slightly different from that of luminaires located further away. This effect can be
minimised by coordinating the air-conditioning system with the lighting system.

Manufacturing tolerances

There may be minimal differences in the light colours of lamps from different manufacturers. In
applications in which colour consistency is a critical factor, all the lamps in a particular zone should
come from the same manufacturer and should all be replaced together. If lamps are replaced indi-
vidually there may be differences in light colour.

Dimming

When fluorescent lamps are dimmed there is a slight reduction in colour temperature. The colour
temperature of a fully dimmed OSRAM DULUX

®

L 36 W lamp, for example, is around 150 K lower

than that of an undimmed lamp. The colour difference appears greater to the eye due the consider-
able differences in luminance. Even greater differences may occur temporarily if there is a sharp
change in the dimmer setting (see 4.7 and 5.1.4).

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