miner's lamp[′mīn·ərz ‚lamp]
a battery-powered lamp used by persons moving from place to place in mines or working at a fixed location; it is also used as a standby light source where illumination is normally supplied from an electric distribution system.
There are two types of miner’s lamps: hand-held and head-mounted. The storage batteries of the latter are fastened to the belt, and the lamp is mounted on the miner’s helmet. Head-mounted lamps are the only type used in mines in the USSR. The best types have a hermetically sealed storage battery. In the USSR such batteries are provided for models SGG-3 and SGG-lk, hermetically sealed head-mounted lamps, in which the battery is charged through the head lamp and a cable. This design makes it possible for miners to service the lamps themselves. Each miner is assigned a lamp and a charging position on the battery charger. The lamp is rated at 30 lumens and will operate a minimum of 10 hr; the weight is approximately 2 kg. Models SGG-3 and SGG-lk are approved for use in mines where there is a gas or dust hazard.