Some alarm systems are tied to video surveillance systems so that current video of the intrusion area can be instantly displayed on a remote monitor, not to mention recorded. Some alarm systems use real-time audio and video monitoring technology to verify the legitimacy of an alarm.
Pipe(noun) any long tube or hollow body of wood, metal, earthenware, or the like: especially, one used as a conductor of water, steam, gas, etc. Pipe(noun) a small bowl with a hollow steam, -- used in smoking tobacco, and, sometimes, other substances.
1 Diameter refers to outside diameter of a pipe or fitting.  The North American standard is known as Nominal Pipe Size (NPS). The International Standard is known as Diameter Nominal (DN). Pipes and fittings are actually made in similar sizes around the world: they are just labeled differently.