Notorious for loud sirens and strobing lights, fire alarms aren’t normally anyone’s idea of a pleasant wall ornament. Yet still, no one can deny the importance of such fire detection devices. Whether it’s alerting the residents of a house that caught fire in the middle of the night or warning shoppers of a flammable accident in a department store, fire alarm sensors are life-saving devices essential to modern infrastructure. But you can’t just buy the first fire detection device that pops up on the market. The devices differ. One built with a sensor made to detect smoke but not gas might take too long to register the presence of a gas fire. Thus, most fire alarms fall into three categories, depending on the type of fire detection sensor they use:
- Flame Detectors
- Smoke Detectors
- Fire Gas Detectors
Today, many fire detection devices on the market employ two or more of these sensor technologies to achieve better results, whether detecting fires or avoiding false alarms. So it’s important to understand the technology used in each sensor type in order to determine the best fire alarm for your home or business. Keep reading to learn more about the different types of sensors, along with some key factors to consider when finding the right fire detection device for your fire protection system.
One aspect of a fire that alarm sensors can detect is heat radiation. Open flames emit heat radiation by transferring energy via electromagnetic waves. Flame detectors come equipped with an electromagnetic radiation receiver, which can distinguish radiation based on wavelength measurement. Specifically, their sensors can detect spikes in heat radiation over certain threshold values for either ultraviolet (UV) radiation or infrared (IR) radiation. Since UV and IR radiation have different wavelengths (between 10 and 400 nanometers for UV and 700 and 1,000,000 nanometers for IR), flame detectors differentiate based on the radiation type they were built to detect. UV flame detectors work by measuring levels of atmospheric radiation. They’re so sensitive that they can accurately detect a flame at the moment of ignition, within milliseconds, and can even detect other sources of UV, like lightning and direct sunlight. As such, many UV flame detectors follow a 2-3 second delay to curtail false alarms from natural UV sources. Meanwhile, IR flame detectors analyze spectral patterns with a thermal imaging camera that renders IR radiation to visible light. Clocking in with a response time of 3-5 seconds, IR detectors don’t react as quickly as their UV counterparts, but they still get the job done and provide ample warning should open flames pop up.
Another, more obvious byproduct of fire is smoke. And with sensors that employ optical technology, smoke detectors can raise an alarm as soon as there’s smoke. Optical (photoelectric) technology gathers light from a source into a single beam, and then a photoelectric sensor converts that light beam into an electrical current that, when scattered by passing smoke particles, increases its voltage to trigger an alarm. These types of smoke detectors are good for sensing smoldering fires with lots of smoke and little visibility, but are vulnerable to false alarms triggered by dust and dirt.
Fire Gas Detectors
Depending on the materials burning, fire can emit a multitude of different gases, sometimes toxic. But fire gas detectors, which are built to register gas at predefined concentrations, utilize this byproduct of fire to raise alarms as quickly as gas is emitted. The technologies these types of detectors use vary from infrared point sensors to ultrasonic sensors to electrochemical gas sensors. But since these detectors are only designed to detect specific gases, careful consideration should be used when selecting the right fire gas detector for your business or home.
Final Factors To Consider Before Buying a Fire Detector
At this point, it should be clear that no one method of fire detection works for every situation. Each application is unique. Therefore, it’s essential to identify your specific fire risks before purchasing a fire alarm sensor. Risks can be broken down into two categories: combustible factors (such as the types of nearby combustibles, their ease of ignition, and their propensity for smoke production) and environmental factors (like temperature, cleanliness, and environmental humidity). Only when you fully analyze your most pressing fire risks can you identify the best fire detection device to protect your home or business, so consider these factors thoroughly.
At Video and Sound Services, Inc., we help companies and homeowners set up surveillance systems. We work with audio and video surveillance equipment often and can help you find the right equipment for your needs. Call us at (708) 562-6316 to upgrade your system.