EXPLOSION DANGER

Greymouth Evening Star, 31 December 1940, Page 2

EXPLOSION DANGER

SAFER LIGHTING SOUGHT. Many users of electric lamps will have wondered whether the hot filaments are liable to cause fires when the bulbs are broken by explosions. Experiment shows that .a lighted filament lamp does not easily >set fire to cotton wool when broken in contact with it, so the ordinary lamp is relatively safe in domestic surroundings. But it is more dangerous when/in contact . with explosive dust or vapours.

According to the “Electric Times,” the United States Navy is experimenting with mercury fluorescent lamps for illuminating powder magazines. In these lamps the inner surface of the tube is covered with a powder which fluoresces under the influence of the invisible ultra-violet rays emitted by the excited mercury vapour. Thus energy which would otherwise be lost is converted into visible light. Ordinary electric lamps in battleships and submarines are liable to be broken by the concussion of gunfire or depth charges, and their exposed filaments might ignite stray powder. Fluorescent lamps emit much less heat and under these conditions are safer. They may also be useful _in mines, gasworks, petrol factories, hydrogen plants, and other places subject to the presence of explosive dust or gas, • •