Presentation on theme: "Florida Supplement B Learning Objective. B.1Describe the operating principle and limitations of thermal-imaging cameras (TICs). B.2 List the advantages."— Presentation transcript:
Florida Supplement B Learning Objective
B.1Describe the operating principle and limitations of thermal-imaging cameras (TICs). B.2 List the advantages and disadvantages of using TICs. B.3 Define intrinsically safe and explain its application with reference to TICs. B.4 Use a TIC to identify hotspots. B.5 Use a TIC as a member of a team in a simulated smoke and fire condition. B.6Take action to maintain team safety as either operator or team leader, given simulated smoke and fire conditions and a TIC failure. B.7Conduct a service check and perform maintenance of a TIC.
Thermal imaging cameras (TICs) have gained acceptance gradually just like many other new products in the fire service. While the acquisition of TICs by a department can be a costly endeavor, their numerous uses make the devices some of the most versatile tools a firefighter can use. Unfortunately, many TICs are left on the apparatus during a fire. The capabilities of TICs greatly increase the effectiveness of firefighters, making their acceptance and use critical.
The concept of thermal imaging is traced back to the 1800s and British astronomer Sir William Hershel. Hershel discovered that colors below the color red in the visible spectrum are invisible to the naked eye without the use of a prism. These calorific rays, now known as infrared rays, are the basis for today’s TIC technology.
All objects emit energy in the infrared spectrum. The hotter the object, the greater the energy release. Rays of energy exist in a spectrum. From low to high, these rays include the following: Radio wavesRadio waves Infrared wavesInfrared waves Visible light waves (red, yellow, blue, and purple)Visible light waves (red, yellow, blue, and purple) Ultraviolet wavesUltraviolet waves X-raysX-rays Gamma raysGamma rays
As with many technical advances, thermal imaging technology was developed for military use. The technology, originally known as FLIR (forward looking infrared), was used in the Falklands War of 1982 by British soldiers to observe movements of enemy troops. This technology was soon added to military aircraft and widely used in the first Gulf War. Military personnel found that use of the thermal imaging technology gave them the advantage of sight in otherwise zero-visibility conditions. The technology also allowed personnel to detect targets from the landscape by their heat signatures.
The application of thermal imaging technology following the Falkland War has expanded in the following progression: Mid 1980s — Adoption by European fire organizations Late 1980s — Adoption by the Fire Department of New York (FDNY) in 1988 Mid 1990s — Adoption and acquisition by other fire departments in the U.S. Today — Widespread acquisition in the U.S. with infrequent application
Functions TICs work by dispersing infrared rays and then interpreting what is found at the infrared level in a format that can be easily seen. In low-visibility environments, visible light is blocked by particles such as smoke, fog, and steam. The infrared rays emitted by the TIC go between these particles and determine the relative temperature of objects in relation to their surroundings. As a result, personnel using TICs have a readily available view of the area based on the heat emitted by objects.
The majority of TIC units are handheld. New technology, however, allows for the production of increasingly smaller units. This newer technology allows TIC units to be directly mounted to firefighters’ helmets and affords personnel the ability to operate with their hands free. TICs vary depending on several factors such as the following: Resolution or pixel count — Resolutions are typically 160 by 120 at the low end and 320 by 240 at the high end.Resolution or pixel count — Resolutions are typically 160 by 120 at the low end and 320 by 240 at the high end. Hertz speed — Signal frequency; the higher the speed the better.Hertz speed — Signal frequency; the higher the speed the better. Electronic iris — Operation is similar to a camera lens; an automatic iris is preferred.Electronic iris — Operation is similar to a camera lens; an automatic iris is preferred. Dynamic range — Range of temperature between the ambient temperature and the highest temperature identified; the wider the range the better.Dynamic range — Range of temperature between the ambient temperature and the highest temperature identified; the wider the range the better. Temperature — Maximum temperature identified on a display. Some units identify temperatures up to 300°F, while others identify temperatures at 1,000°F or more.Temperature — Maximum temperature identified on a display. Some units identify temperatures up to 300°F, while others identify temperatures at 1,000°F or more. Color — Some have black and white displays. Others display various colors depending on the temperature.Color — Some have black and white displays. Others display various colors depending on the temperature.
TIC displays use either LCD (Liquid Crystal Display) or OLED (Organic Light-Emitting Diode) technology. The display of a TIC is typically the single largest power draw of the device. Portable TICs use batteries to provide power to the device. Traditionally, these units have used rechargeable NiCad battery packs, but there has been a more recent trend towards using standard alkaline batteries.
People are often confused of the difference between thermal imaging and image intensifying (better known as night vision) technology. Image intensifiers or night vision goggles take the available visible light and greatly amplify it in order to allow for vision in low-light environments. While people using this technology are able to see in low- light environments, the displays do not indicate relative or specific heat.
Advantages, Disadvantages, and Limitations Just like any other firefighting tool, TICs have advantages, disadvantages, and limitations, which are listed as follows: Advantages — TICs: Are not affected by weatherAre not affected by weather Allow firefighters to see in zero-visibilityAllow firefighters to see in zero-visibility Quickly identify heat sources, especially in overhaulQuickly identify heat sources, especially in overhaul Facilitate victim identification faster during search and rescue operationsFacilitate victim identification faster during search and rescue operations Improve the survivability of interior operationsImprove the survivability of interior operations Contribute to the reduction of both firefighter and civilian deathsContribute to the reduction of both firefighter and civilian deaths
Disadvantages — TICs: Will not penetrate glass, however heated glass typically appears lighter in colorWill not penetrate glass, however heated glass typically appears lighter in color Will not typically penetrate water; some penetration may occur in a fog or mistWill not typically penetrate water; some penetration may occur in a fog or mist May or may not penetrate steam depending on its densityMay or may not penetrate steam depending on its density Will display reflections from surfaces such as glass, water, mirrors, and other shiny surfacesWill display reflections from surfaces such as glass, water, mirrors, and other shiny surfaces Present a two-dimensional image, which means that depth- perception skills must be developedPresent a two-dimensional image, which means that depth- perception skills must be developed Limitations — TICs: Are expensive and may be cost prohibitive for some departmentsAre expensive and may be cost prohibitive for some departments Have the potential to fail just like any toolHave the potential to fail just like any tool Are not beneficial unless usedAre not beneficial unless used
Perhaps the largest limitation of TIC units is the perception and bias of firefighters. Departments that have adopted and widely use TICs find the units are valuable for size-up, search and rescue, fire suppression, ventilation, overhaul, the location of accident victims, the location of hazardous materials, the location of overheated electrical equipment, and many more. New capabilities of TICs are constantly being discovered and implemented.
Future The future of TIC use in the fire service is very promising. Many more departments are requiring a TIC unit on every apparatus. Some progressive departments have gone a step further and outfitted every firefighter in their department with TIC units that are integrated into the helmet. While cost is a factor for TIC purchase, departments can expect that the cost of these units will decrease with time. Given the multiple uses of TICs, these units are a sound investment.