Ionisation smoke alarm
The most common causes of false alarms are:
Ionisation smoke alarms operate on the principle that the electrical current flowing between electrodes in an ionisation chamber is reduced when smoke particles enter the chamber.
Ionisation smoke alarms are more sensitive to smoke containing small particles such as rapidly burning flaming fires but are less sensitive to steam. As a result of this, they are recommended for use in hallways and stairwells adjacent to bathrooms or shower rooms to reduce the number of unwanted false alarms.
Ionisation smoke alarms should conform to BS EN 14604: 2005 - Smoke Alarm Devices.
 Related articles on Designing Buildings Wiki
- Building regulations.
- Scottish building standards.
- Carbon monoxide detector.
- Combustion appliance.
- Fire and rescue service.
- Fire dampers.
- Fire detection and alarm system.
- Fire detector.
- Fire protection engineering.
- Fire safety design.
- Heat alarm.
- Intruder alarm.
- Multi-sensor alarm.
- Optical smoke alarm
- Principal habitable room.
- Smoke detector.
- The causes of false fire alarms in buildings.
- The role of codes, standards and approvals in delivering fire safety.
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