Chapter 3 of NFPA 731 contains general definitions used in the standard. It is important to understand what is considered a “Detection”.

Detection refers to recognizing any unauthorized entry or activity in a specific location on the protected premises.

When a security breach occurs through a window, door, roof or zone of a specific protected area, detection is critical. A security breach can be detected in many forms such as glass breakage, sound, temperature, movement and the like.

When an unauthorized person climbs through an open window or door, window or door sensors detect the intrusion and sound the alarm—doing everything from emitting a loud siren to triggering the main security system and sending an alert to the central monitoring station.

Below is a sample of NFPA 731. For the complete section, see the actual NFPA 731 text at NFPA.ORG. Once there, click on the free access link to the latest edition of NFPA 731.

3.3.9 Detection.

3.3.9.1 Intrusion Detection. The ability to detect the entry or attempted entry of a person or vehicle into a protected area.

3.3.9.2 Sound Detection. Recognition of an audio pattern indicative of unauthorized activity.