In this subtitle the following words have the meanings indicated. “Long–life battery” means a nonrechargeable, nonreplaceable primary battery that is capable of operating a smoke alarm for at least 10 years in the normal condition. “Sleeping area” means a space that includes one or more sleeping rooms and a hall or common area immediately adjacent to any sleeping room. “Sleeping room” means an enclosed room with a bed arranged to be used as a bedroom. “Smoke alarm” means a single or multiple station device that detects visible or invisible products of combustion and includes a built–in internal alarm signal. “Smoke detector” means a system–connected smoke sensing device tied to a fire alarm control panel or a household fire warning panel.