An incandescent lamp with a gas filling to which a certain proportion of a halogen has been added in order to minimise blackening of the envelope by returning evaporated tungsten to the filament.
It is usually characterised by exceptionally small size in relation to the high luminous intensities which can be obtained.
Note: The Tungsten-Iodine Lamp or Quartz-Iodine Lamp belongs to this category.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM