OSRAM DULUX F - Manual (Page 94)

Economical long-life light sources with plug-in bases
Compact Fluorescent Lamps OSRAM DULUX ®
Technical Guide
92
7.5 Temperature measurements
The luminous flux and hence the luminous efficacy of OSRAM DULUX ® lamps depend on the
temperature. To achieve optimum operating conditions for the lamp in the luminaire, it is therefore
essential to know either the ambient temperature in the vicinity of the lamp or the cold spot
temperature directly on the lamp.
7.5.1 Ambient temperature
Unless otherwise indicated, the lamp data in this guide is based on an ambient temperature of 25ºC
± 1ºC in draught free air in accordance with IEC 60901. Lamp data as a function of actual ambient
temperature or cold spot temperature is also measured in draught free air.
7.5.2 Cold spot temperature for lamps without amalgam
The cold spot temperatures are dependent on the operating position and lie approximately in the
range from 40ºC to 50ºC (optimum operating conditions). In the base-up operating position and no
air circulation, temperature measuring point 3 (see 4.8, p. 71 – Lamp temperatures and limit values)
generally corresponds to the cold spot. The cold spot can however shift as a result of a different
operating position or other influences.
Measuring point 3 (cold spot temperature in base-up operating position) is
defined for OSRAM DULUX
® lamps at the outer lamp arc, centred on the bulb
– except CFL SQUARE ® (see 4.8, p. 71). To determine the temperature at
measuring point 3 (not in the case of the CONSTANT version and CFL
SQUARE
® ) thermocouples (NiCr-Ni thermo-elements) are fixed with a neutral,
translucent adhesive.
To avoid an accidental release of the thermocouple, it is highly recommended
to secure it with a small transparent cable tie (temperature resistance of the
material > 120°C) throughout the whole measurement. Refer to the picture below.
7.5.3 Measuring CONSTANT lamps
CONSTANT lamps are designed for a wide temperature range. They therefore achieve their
optimum operating conditions (>90% of rated luminous flux) in the temperature range from 5°C to
70°C. If photometric measurements are taken under reference conditions (an ambient temperature
of 25ºC, see 7.5.1), it must be remembered that the measured luminous flux may be up to 10%
below the maximum luminous flux that the lamp can produce. Please refer to the luminous flux/
ambient temperature relation graphs (4.6) for detailed information.
In case of horizontal operation of quad and multilimbed lamps it has to be noted that the luminous
flux as a function of ambient temperature also depends on the location of the electrodes (above or
below the symmetry plane of the lamp).