Installing a smoke alarm in your home may be one of the most important things you can ever do to increase your safety. A smoke alarm is a small, usually white round device that you mount on your ceiling or high up on the wall. When a smoke alarm detects smoke, it lets out a very loud, high pitched beep that warns everyone in the house that there is the danger of a fire. A smoke alarm is considered one of the three most important fire safety devices you can own along with a fire extinguisher and a fire blanket. They are fairly inexpensive, and most experts recommend you have at least two in your home.
Smoke alarms work in one of two ways. Some are optical, meaning that they include a light sensor. During normal use, a beam of light is detected by the optical detector and nothing happens. However, when smoke enters the smoke alarm, it cuts off the beam of light. When the full force of the light fails to hit the sensor, the alarm is triggered. These types of alarms are very quick to response to smoke caused by smoldering fires; however, they are slower in detecting smoke from flaming, hot fires. They are also less likely to signal a false alarm or be set off by cooking fumes and steam.
Smoke alarms that use ionization, on the other hand, detect smoke from hot fires about 30 seconds before an optical alarm would. They are also cheaper. However, they can be set off more easily and may be set off by cooking. Basically, an ionization alarm works by sending a small current back and forth between a set of electrodes. When smoke enters the smoke alarm, it actually absorbs alpha particles in the alarm, reducing the ionization and causing the alarm to go off.
Smoke alarms typically run off batteries. This has both a good and a bad side. On the positive side, it means they will continue to work even if your home has no electricity. On the downside, you will need to remember to regularly test them and replace any old batteries. Smoke alarms generally feature a test button that will tell you if the battery is getting low, and many will start to emit a regular beep when the battery is almost empty.
Surprisingly enough, smoke alarms have actually been around for decades. The first real automatic smoke alarm was invented back in 1890 by Francis Upton, a contemporary of Thomas Edison. However, this alarm was not mass produced. Walter Jaeger, a Swiss physicist and inventor created another version of the smoke alarm in the 1930s, although he did it by accident—he was really trying to create a device to detect poison gas. Again, though, his device was not mass produced.
Home smoke alarms finally became available during the 1960s. However, these devices were very expensive, and only large businesses had them installed. They were also somewhat larger than today’s smoke alarm. Finally, in 1965, a battery-powered smoke alarm was created. These units were easily installed in the home, making them very popular. However, they would not be mass produced until 1975, when the Statitrol Corporation made smoke alarms widely available.
Today, over 85% of all homes in the UK feature smoke alarms. However, it is important to note that many studies have shown that up to 30% of these smoke alarms are not working properly. Many people forget to replace the batteries in their smoke alarm or simply take the battery out when it starts to beep the annoying low battery noise. For the safety of you, your family, and your home, always remember to test your smoke alarms once a year and replace their batteries as needed.