The Photoelectric VS Ionization smoke alarm debate

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Getting an understanding of the hardware that is protecting you and your families is always invaluable. With smoke alarms, an important place to start is by asking the question "what type of smoke alarm is in my property/ies"? In most cases, the answer to this will take the form of either a Photoelectric smoke alarm or an Ionization smoke alarm. Questioning your alarm type often then brings up the questions 'what is the difference'? and 'does it matter'? To help shed some light, here is a breakdown of how both alarms function in detecting smoke.


Ionization alarms

Ionization alarms are essentially radioactive sniffer dogs. The alarm functions by balancing a small amount of radiation between two magnetic plates. This small amount of radiation converts air molecules that funnel through the alarm into positive and negative ions. The ions will then flow to the positive and negative plates within the top and bottom of the alarm creating a circuitry path out of the converted air molecules. Once smoke enters the alarm's chambers the path of created ions bond with the smoke entering the alarm, which then breaks the molecule circuit between the plates, triggering the alarm.

Ionization alarms are known as a 'smelling' alarm as the smoke needs to fill the chamber and be sensed by the ion cycle to trigger the alarm in the same manner as needing an odour to fill your nostrils for your body to register a smell. 

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Photoelectric alarms

Photoelectric alarms are the eyes of the house when it comes to smoke detection. They work by having a beam of light positioned above a light sensor. When a fire begins to smoulder, smoke particles will enter the alarm and deflect light from the beam of light positioned within the alarm. Once the smoke particles deflect the beams light they interfere with the path of the beams from one side of the alarm to the other, cutting off the path of light within the alarm by deflecting light towards the light sensor, therefore activating it to warn the detection of smoke. 

Photoelectric alarms are the 'seeing' alarms as they sense fires through light and interference of lights pathways, similar to how we notice items when they are put within our line of sight.

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Which is safer?

So which is safer? Photoelectric would be the best choice because it creates a greater chance of safety. Photoelectric alarms can detect fire at its early stages through its visual sensor that triggers off reflections from smoke particles. They are more sensitive detectors, meaning they are able to sense fires at the smouldering stage before it escalates. Ionization alarms require the smoke alarms chamber to fill with enough smoke that the ions react to the smoke particles and break the air molecule circuitry. This means fires will need to develop enough to fill the alarm chamber with smoke, alerting those within the property of the fire at a much later stage of detection. Fire authorities encourage the use of photoelectric alarms as it gives those within the property the foresight to leave at the early stages of a fire.

At Smoke Alarms Australia, our main concern is giving tenants, landlords and agents the greatest chance for safety and security against the risks of fire for themselves and their properties. That is why we only use photoelectric smoke alarms in all our smoke alarm services.

If you have any questions or would like to get in touch with one of our Business Development Managers, click the contact us button below and leave a message regarding your inquiries around alarm types or any other smoke alarm matter.