Photoelectric vs Ionisation
When choosing a smoke alarm, it is important to know that different models use different methods to detect smoke. There are two main types of smoke detectors: ionisation, and photoelectric types. Each is specifically designed to detect different types of smoke, and give the earliest possible warning in the event of a fire.
The amount of warning given depends on the type of combustible material that is burning, and the type of alarm selected for your home. The more warning you get, the more time you have to escape the deadly toxic smoke and flames.
Ionisation type alarms respond faster to small smoke particles, such as those given off by burning paper, straw, or wood.
Photoelectric alarms respond faster to larger smoke particles, such as those produced by burning foam, rubber, plastics and other synthetic materials.
Nowadays, most homes are filled with synthetic materials. These include nylon found in carpets and curtains, plastic consumer goods and the foam rubber found in a lounge chair or mattress of your bed.
Therefore the best detector type for your home is usually a photoelectric detector type. For the ultimate protection, a combination of both ionisation and photoelectric is recommended.
Typical applications
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MODEL |
TYPE |
TYPICAL APPLICATIONS |
|
755PSMA
755PFM |
Photoelectric |
- Lounge
- Living areas
- Bedrooms
- Rumpus
|
| |
755SMA
755FM |
Ionisation |
- Hallway
- Corridor
- Study/ Home office
|
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Battery vs Mains Powered
Smoke alarms can either be mains powered, or battery powered. Battery powered smoke alarms are commonly available from supermarkets and hardware stores. These types of alarms DO NOT comply with the required regulations for new buildings, as they offer an inferior level of protection.
Battery alarms have a big weakness – they rely on YOU to test and change the battery on a regular basis. All too often we get lazy or forget to do this, and the results can be catastrophic. In the event the battery goes flat, the alarm cannot detect smoke, and will not alert you to any danger.
All mains powered smoke alarms have a continuous source of power and also incorporate a backup battery. That way the alarm can respond to the presence of smoke, even if the mains power is cut.
Mains powered smoke alarms also offer features that are not available in battery powered models, including the ability to be interconnected.
Mains powered smoke alarms can also be interconnected so that when one alarm trips, all units will sound – ensuring adequate warning and the best possible reaction time.
Why insist on mains powered?
"Where battery powered alarms are present, up to 40% of them are non-functional due to poor maintenance or flat batteries."
Australian Bureau of Statistics
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