... life span. However, in the case of infraredlamp, the filament will not be easily broken because it remains lowtemperature. ... , ambient air penetrates into the lamp andcombines with filament, resulting in burning of filament.Especially, in the case of red-coated far ... , ambient air penetrates into the lamp andcombines with filament, resulting in burning of filament.Especially, in the case of red-coated ...