DS9840 OSRAM, DS9840 Datasheet - Page 25

• Manufacturer Part Number: DS9840
• Description: LAMP, DULUX, S, COOL, 9W
• Manufacturer: OSRAM

Specifications of DS9840

• Supply Voltage: 60V
• Base Type: 2 Pin
• Power Rating: 9W
• Luminous Flux: 600lm
• Length: 167mm
• Colour Temperature Typ: 4000K
• Svhc: No SVHC (15-Dec-2010)
• External Depth: 19.5mm
• External Diameter: 19.5mm
• External: RoHS Compliant
• Lamp Base Type: 2 Pin
• Rohs Compliant: Yes
• Average Bulb Life: 8000h
• Bulb Diameter: 19.5mm

Economical long-life light sources with plug-in bases.
Compact Fluorescent Lamps OSRAM DULUX
Technical Guide
24
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 „rain-
bow“ effect when use in conjunction with trichrome phosphors. Since all OSRAM
DULUX
be wrongly ascribed to the lamps as „different light colours“.
Ambient temperature
The light colour of trichrome 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 luminaires 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 manufac-
turers. 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 individually 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
is around 150 K lower than that of an undimmed lamp. The colour difference appears
greater to the eye because of the considerable difference 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).
Ageing
Generally speaking, there are no changes in colour temperature or shifts in chromati-
city coordinates in the course of a lamp’s service life. However, lamps do suffer a drop
in luminous flux as they age (see 2.4) and it is the resulting difference in luminance
between an old lamp and a new lamp that give the impression of a change in colour
temperature.
®
lamps contain trichrome phosphors, this effect caused by the reflector may
®
®
L 36 W lamp, for example,
2. Lamp data