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.
Invert of the pipes in and out is the elevation at the bottom of the inside pipe wall, not the bottom of the pipe. Invert of the structure (MH or inlet) is the bottom of the inside of the structure, not the excavation depth. Engineering is the practice of the art of science - Steve.