OSRAM DULUX F - Manual (Page 64)

Economical long-life light sources with plug-in bases
Compact Fluorescent Lamps OSRAM DULUX ®
Technical Guide
62
4.6 Luminous flux as a function of temperature and operating position
OSRAM DULUX ® lamps achieve 100 % luminous flux at ambient temperatures of 15ºC or 25ºC
respectively, depending on the operating position, after a certain run-up time has elapsed, as the
graphs above show (see 4.3).
The OSRAM DULUX ® HE range achieves 100% luminous flux at an ambient temperature of about
35°C.
For free-operating lamps, the ambient temperature corresponds to the room temperature. If lamps
are operated in luminaires, the temperature in the immediate vicinity of the lamp is the one that is
relevant to any measurement of luminous flux.
The lamps can be operated in any operating position. However, different burning positions and
different ambient temperatures will lead to different luminous flux values. This is due to temperature
changes at certain locations on the lamp.
OSRAM DULUX ® , OSRAM DULUX ® HE, SP, XT and ES lamps which use the standard Cold Spot
technology, luminous flux is controlled by the so called Cold Spot. For this reason, we speak of the
cold spot temperature. This temperature affects the mercury vapour pressure in the lamp and
therefore the luminous flux. The luminous flux/temperature graph depends on the operating position
of the lamp. Different operating positions cause the cold spot to be heated in different ways and
reach different temperatures. Knowledge of the luminous flux/temperature graph is important for
light fitting designers. The base-up operating position is preferred for indoor lighting, for example,
whereas the base down operating position for out-door lighting (compare the values at 0 ºC, for
example).
For OSRAM DULUX ® CONSTANT technology based lamps, amalgam controls vapour pressure and
luminous flux. Similarly to the cold spot, the amalgam temperature is affected not only by the
ambient temperature, but in certain way by the operating position of the lamp. And so the luminous
flux/temperature graphs for different operating positions are different.
OSRAM DULUX ® , HE, OSRAM DULUX ® CONSTANT lamps are optimised for various temperature
ranges.
OSRAM DULUX ® CONSTANT lamps are ideal for high ambient temperatures. They produce 90 % of
their maximum luminous flux over a wide temperature range from 5°C to 70°C. Installed in a suitable
light fitting, the lamps are able to achieve high performance even under cold ambient temperatures
too.
If OSRAM DULUX ® CONSTANT lamps and OSRAM DULUX ® Cold Spot lamps are combined in the
same installation there will be visible differences in colour perception and brightness. For this
reason these two types may not be mixed.
Depending on the operating position the maximum luminous flux will be reached only after a certain
Run-up time (see 4.3). Under optimum conditions in magnetic ballast and ECG operation, all the
lamps require an aging period of 100 h.
For DULUX D, DE, T, T/E and CONSTANT multilimbed lamps in horizontal operating position it is
important to know that the location of the electrodes (facing towards to or facing away from the
reflector) has a direct impact on the performance of the lamp. Differences in luminous flux or
brightness will appear. Electrodes facing towards to the reflector will result in a maximum luminous
flux at higher ambient temperature than for the case with the electrodes facing away from the
reflector. On the other hand, with the electrodes facing towards to the reflector the cap temperature
will be significantly increased compared to operation with the electrodes facing away from the
reflector (see 4.8.1).
Note that it is essential for the design of the luminaire to perform the light and temperature
measurement for both kinds of horizontal lamp orientation. Under any conditions the maximum
lamp cap temperature may not be exceeded.