To overcome the luminous flux temperature dependence of mercury low pressure fluorescent lamps a new generation of lamps in amalgam technology has been introduced. The products are named T5 HO CONSTANT and DULUX L CONSTANT as they show a very high luminous flux over a wide ambient temperature range.

Actual T5 lamps on the market have their maximum luminous flux at 35°C (compared to 25°C for T8), and still show good (more than 90% of maximum luminous flux) performance from about 25°C to 50°C ambient temperature. For DULUX L the corresponding optimum temperature range is in between 20°C and 45°C.
With the new T5 HO CONSTANT and DULUX L CONSTANT OSRAM is the first manufacturer in the world to offer T5 and DL lamps which also have a high luminous flux (Phi>90%) at ambient lamp temperatures below 25°C down to 5°C and above 50°C up to 70°C.

The new technology of HO CONSTANT lamps is not yet fully covered by electronic control gear on the market ? thus the lamps can not yet be fully released for dimming. Our actual tests on OSRAM ECG show that the lamps can be dimmed down to 30% without problems, and can also be ignited at settings of 30% to 100%. We do not recommend dimming to or igniting at below 30% and will not warranty the lamp in such cases. OSRAM is of course working with high priority on this issue, and will update this web-site as soon as the situation changes.

For project applications where certain dimming levels are required, please contact us to discuss if a special release is possible.