Difference Between Tungsten Filament Lamps and Fluorescent Tubes:
The Difference between tungsten filament lamps and fluorescent tubes is given in table below
|Tungsten Filament Lamps
|Voltage fluctuation has comparatively more effect on the light output.
|Voltage fluctuation has comparatively low effect on light output as the variations in voltage are absorbed in the choke.
|Luminous efficiency increases with the increase in voltage of the lamp.
|Luminous efficiency increases with the increase in wattage and increase in length of tube.
|It gives light close to natural light, therefore, objects are properly seen.
|It does not give light close to natural light, therefore, colour rendering is defective.
|Luminous efficiency of coloured filament lamps is poor because coloured glasses are used for this purpose.
|Different colour lights can be obtained by using different composition of fluorescent powder. Hence efficiency is high and better colours are obtained.
|Due to comparatively high working temperature heat radiations are also present.
|Due to low working temperature heat radiation is low.
|Its brightness is more.
|Its brightness is less.
|With the time light output is reduced.
|With the time light output is gradually reduced.
|No stroboscopic effect.
|It has objectionable stroboscopic effect.
|Though the life of filament lamps varies with the working voltage, however, its normal life is 1,000 working hours.
|Life of fluorescent tubes is not affected so much by variations in voltage but it depends on the frequency of starting. The life of the tube is about 7,500 working hours.
|The initial cost per lamp is quite low.
|The initial cost per tube is more.
|For same lumens output more lamps are required and wiring cost is more. Life of lamp is also low. Hence overall cost of maintenance is more.
|For same lumens output, lesser number of tubes is required, the wiring cost is low. Since its life is comparatively more, replacement cost is low. Hence overall maintenance cost is low.