Initiating and Detection Devices (Fire Alarm Detectors)

Detectors within a control circuit can pick up heat, smoke and flame. The detector senses the incident and signals the control panel, which processes it and then raises the alarm by sound or by light.

Device types

• Smoke detectors
• Heat detectors
• Manual call points (manual stations)

Smoke detectors

A smoke detector detects smoke automatically. Most fires produce smoke first, so a smoke detector can pick a fire up in its early stages. There are two broad types.

Addressable smoke detector

An addressable detector is the origin of the fire alarm signal and identifies its own position. These devices have to work with an intelligent fire alarm control panel.

Conventional smoke detector

A zone-based system divides the building's controlled area into sections or zones to the standard, giving a search area for locating an incident. This design shows the incident area only as a broad zone, not the exact point, so the exact point may need to be located again. It is usually installed in small buildings.

Heat detectors

A heat detector senses the heat of an object. It is used for fires that develop quickly with little smoke, and in some cases it can detect a fire faster than a smoke detector. Types include fixed temperature and rate-of-rise. There are two broad types.

Addressable heat detector

An addressable detector is the origin of the fire alarm signal and identifies its own position. These devices have to work with a control panel that supports them.

Conventional heat detector

A zone-based device. The building's controlled area is divided into sections or zones to the standard, giving a search area for locating an incident. This design shows the incident area only as a broad zone, not the exact point, so the exact point may need to be located again. It is usually installed in small buildings.

Manual call points (manual stations)

A manually operated device, pulled to raise the alarm when a fire is discovered. It is installed at points where it is easy to see, and comes as a manual pull station or a break glass unit.