What is a Ionisation alarm and where do we use them?

The ionisation alarms from Aico use ionisation type sensors that are sensitive especially to the smoke(which is almost invisible to the human eye) that is produced by the fast flaming fires. This feature causes them to be more liable to false alarms due to the cooking fumes (if they are sited close to the kitchen - in the hallway or other venue). On the other hand, the Aico ionisation alarms are less vulnerable to false alarms caused by dense smoke(tobacco smoke for instance), excessive dust and insect ingress. The British Standard BS 5839: Part 6: 2004 recommends that the ionisation alarms should not be used in landings or hallways - places where there is a high risk of false alarms that are caused by cooking fumes. Alarms: Aico Ei161 RC and Aico Ei141.

Aico Ionisation alarms -
their functioning and where should they be used.

How do the Aico Ionisation Alarms Function?

1. There is a minute(safe) radioactive (inside the sensor chamber) which ionises the air within. This causes a small current to flow in the chamber, and this current remains constant for the life of the alarm (unless some smoke particles enter into the sensor chamber).
2. When / if smoke enters the sensor chamber, the balance of the current is disturbed.
3. This disturbance is detected by the electronics in the alarm circuitry, and the Integral Circuit(IC) is being sent a signal.
4. When the signal is received, the alarms sounds.
5. Quick response to the fast flaming fires.