A Guide To The Photoelectric Smoke Alarm
By Home Safety Store|June 09, 2022
Did you know that an average of 50 Australians die from residential fires each year – which is more than all natural hazards combined? The vast majority of those fatalities could have been prevented with a simple smoke alarm. Installing and maintaining an appropriate smoke alarm detector is not just a legal requirement; it could be a matter of life and death.
But there are two types of smoke alarms on the market (photoelectric and ionisation), so which one is the better choice? The preferred option is the photoelectric smoke alarm – and in this article we will explain why.
The Photoelectric Smoke Detector: What Is It?
Also known as optical or photo-optical smoke alarms, the photoelectric smoke alarm utilises a beam of light to detect visible
smoke particles resulting from combustion.
The device has an enclosed chamber with a light sensor and an LED light inside. The LED shoots a continuous light beam across to the other side of the chamber. When smoke particles pass through the beam, they deflect it towards the light sensor, which trips the alarm.
The Differences Between Photoelectric & Ionisation Smoke Alarms
Photoelectric versus ionisation smoke alarms: what’s the difference?
The photoelectric device uses a steady LED beam and a light sensor, but the ionisation alarm works in a totally different way.
The device has a sensing chamber that ionises the air inside it using a tiny amount of radioactive material. Once the air has been ionised, it effectively conducts an electrical current, which will move freely between two electrodes in the chamber.
As smoke particles enter the chamber, they reduce the conductivity of the air inside, effectively preventing the current from crossing between the two electrodes. When the electrodes stop receiving the current, this triggers the alarm.
The Pros & Cons of Photoelectric Smoke Alarms
The truth is that the ionisation alarm doesn’t perform as well as the photoelectric model in almost all real-world situations.
Photoelectric smoke alarms are proven to be more effective for residential use. The technology responds more quickly to smouldering fires, which are a common occurence in Australian homes. Photoelectric alarms can also rapidly detect dense smoke, which disperses when PVC wiring overheats and foam-dense furniture catches fire—two common house fire causes.
On the downside, photoelectric alarms don’t detect fast flaming fires as quickly as the ionisation system. However, these fires most commonly occur during the day when the homeowner is awake, typically due to kitchen mishaps or the ignition of flammable materials. It is most likely that you’ll witness these incidents in real-time, making it slightly less crucial to receive a warning via a smoke alarm.
Moreover, this slow response time to cooking accidents can work in your favour. Photoelectric alarms don’t detect fast flaming fires as quickly, making them far less prone to nuisance alarms.
False alarms are not only annoying, they can also be deadly. Many householders get fed up and remove the batteries to avoid excessive nuisance alarms – making their smoke alarms completely useless. Several deaths each year in Australia could have been prevented if the homeowner hadn’t removed the batteries from their smoke alarm.
Which Smoke Alarm Type Should You Choose?
Virtually all Australian fire departments and the Fire Protection Association recommend photoelectric alarms for residential use.
Queensland and the Northern Territory now make photoelectric alarms compulsory for use at home. Installing an out-dated
ionisation alarm in these states is against the law and could lead to a fine.
Maintaining Your Photoelectric Smoke Alarm
While installing a photoelectric smoke alarm is the first step toward safeguarding your home, maintaining it properly is also very important.
According to NSW Fire and Rescue, you should do the following:
1. Test your smoke alarm once a month.
2. Vacuum dust off the alarm twice a year to ensure smoke can reach the internal sensor.
3. Replace any lead or alkaline batteries every 12 months.
4. Replace your smoke alarms every 10 years or following the manufacturer’s recommendation.
Get Your Photoelectric Smoke Alarm from Home Safety Store
From mains-powered devices to lithium-ion-charged units, we offer a broad range of state-of-the-art photoelectric smoke alarms.
At Home Safety Store, we believe in putting quality and fire safety standards first at all times. Don’t put your family at risk by purchasing a cheap, no-name alarm. View our catalogue today and buy a reliable unit from a brand you can trust.
But there are two types of smoke alarms on the market (photoelectric and ionisation), so which one is the better choice? The preferred option is the photoelectric smoke alarm – and in this article we will explain why.
The Photoelectric Smoke Detector: What Is It?
Also known as optical or photo-optical smoke alarms, the photoelectric smoke alarm utilises a beam of light to detect visible
smoke particles resulting from combustion.
The device has an enclosed chamber with a light sensor and an LED light inside. The LED shoots a continuous light beam across to the other side of the chamber. When smoke particles pass through the beam, they deflect it towards the light sensor, which trips the alarm.
The Differences Between Photoelectric & Ionisation Smoke Alarms
Photoelectric versus ionisation smoke alarms: what’s the difference?
The photoelectric device uses a steady LED beam and a light sensor, but the ionisation alarm works in a totally different way.
The device has a sensing chamber that ionises the air inside it using a tiny amount of radioactive material. Once the air has been ionised, it effectively conducts an electrical current, which will move freely between two electrodes in the chamber.
As smoke particles enter the chamber, they reduce the conductivity of the air inside, effectively preventing the current from crossing between the two electrodes. When the electrodes stop receiving the current, this triggers the alarm.
The Pros & Cons of Photoelectric Smoke Alarms
The truth is that the ionisation alarm doesn’t perform as well as the photoelectric model in almost all real-world situations.
Photoelectric smoke alarms are proven to be more effective for residential use. The technology responds more quickly to smouldering fires, which are a common occurence in Australian homes. Photoelectric alarms can also rapidly detect dense smoke, which disperses when PVC wiring overheats and foam-dense furniture catches fire—two common house fire causes.
On the downside, photoelectric alarms don’t detect fast flaming fires as quickly as the ionisation system. However, these fires most commonly occur during the day when the homeowner is awake, typically due to kitchen mishaps or the ignition of flammable materials. It is most likely that you’ll witness these incidents in real-time, making it slightly less crucial to receive a warning via a smoke alarm.
Moreover, this slow response time to cooking accidents can work in your favour. Photoelectric alarms don’t detect fast flaming fires as quickly, making them far less prone to nuisance alarms.
False alarms are not only annoying, they can also be deadly. Many householders get fed up and remove the batteries to avoid excessive nuisance alarms – making their smoke alarms completely useless. Several deaths each year in Australia could have been prevented if the homeowner hadn’t removed the batteries from their smoke alarm.
Which Smoke Alarm Type Should You Choose?
Virtually all Australian fire departments and the Fire Protection Association recommend photoelectric alarms for residential use.
Queensland and the Northern Territory now make photoelectric alarms compulsory for use at home. Installing an out-dated
ionisation alarm in these states is against the law and could lead to a fine.
Maintaining Your Photoelectric Smoke Alarm
While installing a photoelectric smoke alarm is the first step toward safeguarding your home, maintaining it properly is also very important.
According to NSW Fire and Rescue, you should do the following:
1. Test your smoke alarm once a month.
2. Vacuum dust off the alarm twice a year to ensure smoke can reach the internal sensor.
3. Replace any lead or alkaline batteries every 12 months.
4. Replace your smoke alarms every 10 years or following the manufacturer’s recommendation.
Get Your Photoelectric Smoke Alarm from Home Safety Store
From mains-powered devices to lithium-ion-charged units, we offer a broad range of state-of-the-art photoelectric smoke alarms.
At Home Safety Store, we believe in putting quality and fire safety standards first at all times. Don’t put your family at risk by purchasing a cheap, no-name alarm. View our catalogue today and buy a reliable unit from a brand you can trust.
