This manual is developed by the Signaling Protection and Communication Section. It provides technical information on basic fire alarm systems with a focus on early-warning smoke detection devices. This document covers smoke detectors connected to a control panel. PURPOSE The purpose of this guide@ is to provide information concerning the proper application of smoke detectors used in conjunction with fire alarm systems. It outlines basic principles@ which should be considered in the application of early-warning fire and smoke detection devices. Operating characteristics of detectors and environmental factors may aid@ delay@ or prevent their operation are presented. Fire protection engineers@ mechanical and electrical engineers@ fire service personnel@ fire alarm designers and/or installers will find this guide's contents both educational and informative. Though this information is based upon industry expertise and many years of experience@ it is intended to be used only as a technical guide. The requirements of applicable codes and standards@ as well as directives of the Authorities Having Jurisdiction (AHJs)@ should be followed. Importantly@ NFPA 72 for installation of detectors and for testing of systems is a key element for the effectiveness of smoke detection systems.