Essential requirements for terminal equipment intended for connection to 2-wire analogue speechband leased lines of the public telecommunications network— 24 стр.
Essential requirements for terminal equipment intended for connection to analogue baseband leased lines of the public telecommunications network— 20 стр.
Explosive atmospheres. Caplights for use in mines susceptible to firedamp. General requirements. Construction and testing in relation to the risk of explosion— 24 стр.