Abstract
By increasing the lamp wattage, a number of fixtures can be reduced or higher illuminance can be achieved.
It is well known that kripton filling lamp shows higher luminous efficacy, while it has higher starting voltage and higher lamp current. Oppositely argon filling lamp has lower lamp current that reduces ballast loss and gives higher luminous flux as a result of higher lamp wattage.
Highly loaded T8-1.2m argon lamp shows fairly good luminous efficacy when operated by electronic ballast.For instance, 40W T8 lamp shows over 100 lm/W which is competitive with 102 lm/W of standard 32W T8 lamp.
To prevent the sputtering of the emmision materials, filament preheating up to the temperature of glow-to-arc transition is important.
