Fire safety is of primary concern in many areas, whether within business establishments, public buildings or in private homes. There are numerous ways that flame detection takes place including optical , thermocouple or ionisation flame detectors. If you are looking for the right type of flame detection, it is important to have a general understanding of the types available and how they function so that optimal safety measures are being put into place depending on the nature of the building and appliances being used.
Optical flame detection systems include ultraviolet detectors, near IR array, Infrared flame detection, UV/IR, IR/IR flame detection, IR3 flame detection, video sensors and video flame detectors. Ultraviolet detectors are popular because the UV radiation is emitted instantly when fires and explosions are ingnited – the time-frame is around 3-4 milliseconds. Visual or near IR array flame detectors use visual flame technology to send off an alarm, while infrared flame detectors incorporate the use of the infrared spectral band technology by way of a thermal imaging camera. However, an important downside to the latter is that flase alarms can go off should other hot surfaces or background thermal radiation be detected by the flame detector as well. Closed circuit or video cameras can also be used as flame detectors but the tendency for the lens to be blocked by smoke can make it a less than desirable choice.
Other types of flame detection devices include ionisation current flame detectors and thermocouple flame detection systems. The ionisation within the body of a flame can be picked up and measured through the current, which will flow when a voltage is applied through ionisation current flame detector types. The benefits of this type of flame detector is that this current can be used to accurately detect and verify the presence of a flame and its potency. This technology is typcially found within industrial process gas heaters. In combustion heating systems and gas cookers a different type of flame detector is used known as thermocouple flame detection. This method acts as a ‘flame failure’ device, which cuts off the supply of fuel if the flame fails to prevent any explosion or asphysiaxtion from occuring. These conclude the main types of flame detection devices available.