How do Smoke Alarms Work?
Smoke alarms are perhaps the single most important form of home security one can own. Thousands of lives are saved each year because of working smoke alarms in the home. However, if a home has a non-working smoke alarm then that home and its residents are at risk. Smoke alarms are actually relatively ingenious considering how inexpensive they are to produce. The majority of smoke alarms have one of two types of detectors built in. The photoelectric detector employs light technology and sensors. Inside a smoke alarm with a photoelectric detector, there are beams of light that radiate at a ninety-degree angle from a built-in sensor. In the event of smoke, the smoke particles interrupt the light beams causing them to reflect off of minute particles and trigger the sensor. This is when the alarm sounds. The other most common type of smoke alarms have ionization detectors that work off of an electrical current created by electrons and ions moving between two internal plates. When smoke ente
It takes nearly four minutes for a small flame to turn in a big fire. There should be smoke alarms in every house and office so that the first whiff of smoke can be detected to save the life of people. Smoke detectors are of mainly two types one is the ionized detector and other is photoelectric detectors. Smoke alarms sometimes use both methods and heat detectors too. The detectors get power from the 9 volt lithium battery or 120 volts from the wiring. IONIOZATION DETECTORS Ionization chamber with the source of ionizing radiation which becomes the source of alpha particles is present in the ionization detectors. This chamber has two plates at a distance of a centimeter. When the power is supplied through battery then one plate gets positively charged and other one negatively. The alpha particles released continuously by the radiation ionize the atoms of oxygen and nitrogen air in the chamber. The negative plate attracts the positively charged atoms of oxygen and nitrogen. And negative
Smoke alarms are one of those amazing inventions that, because of mass production, cost practically nothing. You can buy a general use smoke alarm for $10. And while they cost very little, smoke detectors save thousands of lives each year. In fact, it is recommended that every home have one smoke detector per floor. All smoke alarms consist of two basic parts: a sensor to sense the smoke and a very loud electronic horn to wake people up. Smoke detectors can run off of a 9-volt battery or 120-volt house current. Lets examine the two most common types of smoke alarms used today: photoelectric detectors and ionization detectors. And, we’ll also take a look inside an ionization detector. Well start with photoelectric detectors.
