DS7840 OSRAM, DS7840 Datasheet - Page 22

• Manufacturer Part Number: DS7840
• Description: LAMP, DULUX, S, COOL, 7W
• Manufacturer: OSRAM

Specifications of DS7840

• Supply Voltage: 47V
• Base Type: 2 Pin
• Power Rating: 7W
• Luminous Flux: 400lm
• Length: 137mm
• 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
2.3
2.3.1 Light colours
Photometric
data
The light colours of the lamps are divided into three groups, each covering a particular
colour temperature range.
Light colour
Daylight
Cool White
Warm White
The light colour is determined by the x and y coordinates in the chromaticity table.
For practical purposes, it is important to know the colour rendering properties of the
lamps in addition to their light colour and colour temperature. These properties are
defined by the (general) colour rendering index R
The colour rendering index (computed using the CIE method) provides an indication of
how non-luminous colours will appear when illuminated by the relevant light source.
Colour rendering is assessed by comparison with a Planckian radiator (< 5000 K) and
normalised daylight ( 5000 K) of the same colour temperature. By definition, these
radiators have the ideal colour rendering index of 100. Any deviation from this ideal is
rated with values lower than 100.
The general colour rendering index R
nally standardised test colours (CIE).
There are various ranges for the R
R
90 - 100
80 - 89
70 -79
60 - 69
40 - 59
20 - 39
Note:
The colour perception of a non-luminous colour therefore always depends on the
colour temperature of the illuminating lamp and colour rendering properties of this
lamp.
Example:
Blue tones will always appear brighter in the light from a lamp with a daylight colour
than in the light from a lamp with a warm white colour, even if both lamps have an R
value of 100.
a
value
(according to DIN 5035)
®
Group
1A
1B
2A
2B
3
4
Colour temperature
> 5000 K
3300 - 5000 K
< 3300 K
a
value, known as colour rendering groups:
a
Unsatisfactory
is the average value of eight different internatio-
Satisfactory
Very good
Very good
Good
Good
a
.
2. Lamp data
a
21