Infrared radiations are electromagnetic waves that are invisible to the human eyes. The value of the wavelength of infrared waves lies within the range 740 nm and 4 x {10}^{5} nm. The frequency band of infrared rays typically ranges between 300 GHz and 400 THz. In the electromagnetic spectrum, the infrared radiations are present right in the middle of the microwave radiations and the visible light. The high energy possessed by the infrared radiations is hazardous to health and may cause a person to suffer minute to severe degree burns. Also, infrared radiations are not suitable for the eyes, which is why it is always recommended to wear glasses while operating the appliances that make use of infrared light radiations. Such radiations can be generated either with the help of a luminous generator or a non-luminous generator. The infrared radiations produced with the help of a luminous generator are not pure in nature; whereas, a non-luminous generator is capable of emitting pure Infrared radiations into the environment. The infrared spectrum can be broadly classified into three categories, namely near-infrared, mid-infrared, and far-infrared radiations. The infrared radiations that fall within the wavelength range of 0.75 to 3 micrometres are known as near-infrared radiations. The range of the mid-infrared region typically lies between 3 micrometres and 6 micrometres. Likewise, the infrared radiations having a wavelength above 6 micrometres tend to form the far-infrared region.
Examples of Infrared Waves
There exist a number of applications in our daily life that make use of infrared radiation. Some of them are listed below:
1. Remote Control
The remote controls that are used to control the operation of certain gadgets such as televisions, stereos, toy cars, etc. typically make use of infrared radiations. In such applications, the remote control acts as a transmitter that picks up the command provided by the user and accordingly generates a binary signal with the help of infrared light radiations. The binary coded infrared light radiations are then coupled to the receiver through the air and the operation as per the input command is executed.
2. Optical Fibres
The use of infrared radiations in optical fibre communication is quite advantageous as the wavelength of the infrared radiations is significantly higher than the wavelength of the visible light. The transmission of the signal through the optical fibre cables with the help of such high wavelength electromagnetic radiations reduces the chances of signal deterioration, losses, and attenuation.
3. Thermal Imaging Cameras
Thermal imaging cameras usually make use of infrared radiations to detect and measure the infrared energy emitted by an object. A thermal imaging camera is generally known as an infrared camera or a thermal imager. The working of the camera is quite simple and can be easily summarized into three steps. The first step of imaging involves the collection of the infrared data present in the surroundings. For this purpose, the camera takes the infrared radiations emitted by the objects present in the surroundings and feeds them to the processor. The second step involves the processing of the raw data. The processor of the device tends to convert the input data in the form of an electronic image. The final step is to lay out the processed data on the output screen in the form of an image. The thermal imaging process is typically used to enhance the visualization of objects in low visibility environment.
4. Infrared Cookers
The ability of infrared radiation to produce a huge amount of heat is typically used in infrared cookers. Such devices are typically used in domestic as well as commercial kitchens to heat or cook food. The technology that is used by the infrared cookers to cook and heat food is quite similar to that of the technology used by microwave ovens. One of the prime advantages of using infrared radiations to cook or heat food is that the food cooked with the help of infrared cookers tends to retain more moisture than the food cooked with the help of the traditional convection method. An infrared cooker or heater typically works on the principle of incandescent heating. The internal structure of an infrared cooker typically consists of halogen lamps and an infrared burner. The top surface of the cooker consists of a ceramic plate that has microscopic holes in it. The internal circuitry of the cooker helps convert the heat energy supplied by the burner into infrared energy. The energy possessed by the infrared radiations can be further used to trigger motion into the atoms of the food particles, thereby causing them to vibrate. The vibration of the elements increases the kinetic energy and collision of particles with each other. Due to the collision of particles, heat energy gets produced that can be used to cook or heat the food items.
5. Electric Heaters
A number of electric heaters available in the market make use of infrared light radiation for their operation. The internal structure of the infrared heaters typically consists of three parts, namely infrared light bulbs, a fan, and a heat exchanger. The infrared light bulbs serve to be the main source of energy for infrared electric heaters as they tend to radiate high-intensity infrared light energy into the environment. The heat exchanger is made up of conducting materials such as copper that helps transfer heat from one point to the other. The main purpose of the fan embedded inside the heater is to blow air on the heat exchangers to circulate the heat in the environment. Some of the infrared heaters are fuel-powered and make use of gases such as natural gas, propane, etc. One of the major advantages of using infrared radiations in heating devices is that they are more energy-efficient than conventional heating devices.
6. Infrared Lamps
Infrared lamps are the prime sources of infrared radiation. The commercial application of infrared lamps can be observed in various industries and factories such as pharmaceuticals, chemical industries, etc. The domestic application of infrared lamps can be observed in heating devices, remote controls, etc.
7. Infrared Thermometers
The infrared thermometers are one of the most important applications of infrared radiation in real life. This is because an infrared thermometer helps provide the user with the advantage of easy, fast, and contactless detection of the temperature of the body or an object. The disadvantages of an infrared thermometer include complex maintenance and troubleshooting procedure, high cost, low life span as compared to the traditional thermometers, etc. The working of an infrared thermometer is quite simple. It typically makes use of the concept of emissivity. The infrared light radiation emitted by the infrared thermometer falls on the surface of the object and gets reflected back. This reflected light then gets detected by the detectors present in the internal structure of the device and is processed with the help of various internal readers. Finally, the processed data gets displayed on the screen as output.
8. Infrared Therapy
The ability of infrared radiations to produce heat energy into the environment can be easily utilized in infrared therapy. Infrared therapy mainly aims to cure diseases such as blood clotting, osteoarthritis, or cardiovascular respiratory problems etc. It can also be used to relieve pain, relax or massage the muscles, improve the mobility of joints, increase blood flow through veins, etc. Infrared therapy is quite advantageous; however, the exposure of the infrared radiations should be done in a controlled and precise manner to avoid any sort of negative impacts. Also, infrared therapy must not be used in case a person has a ruptured or blocked artery, or in case his/her skin cells have lost the ability to sense hot or cold substances.
9. Night Vision Goggles
The night vision goggles generally make use of infrared radiation for their operation. The basic working principle of the night vision goggles depends on a process known as image enhancement. Image enhancement is the technique by virtue of which the sense of sight can be increased to a significantly high level by amplifying the already existing light in the surroundings. It can be easily observed that even during the night time or in dark places, some amount of light is always present. This available small amount of light may also contain infrared light radiations that are invisible to the human eye. Certain amplification circuits are generally embedded inside the night vision goggles that help in the amplification of the visible and infrared light radiations present in the surroundings. This helps improve the visibility of the objects present in the dark environment.
10. Infrared Saunas
The application of infrared radiations can be easily observed in the spas and saunas for relaxation and for the treatment of the skin. Infrared radiations are usually preferred for such applications due to their ability of deeper penetration.
11. Waon Therapy
Waon therapy is the process in which a person is made to enter a closed chamber and is exposed to infrared radiations for about 10-15 minutes. The temperature of the chamber is maintained at approximately 60 degrees Celcius. After being exposed to the radiation, the person is externally provided with heat energy with the help of thermal blankets. Finally, a drink such as warm water is given to the person that helps in restoration of the moisture lost due to excessive perspiration. Waon therapy is known to improve cardiac function and release stress.
12. Infrared Astronomy
As the name itself suggests, infrared astronomy makes use of infrared radiations to study the process, nature, and behaviour of cosmological activities, phenomena and objects. This is because there are certain massive cosmological objects present in space that can not be seen when exposed to visible light and are visible only in the presence of infrared radiations. Various observatories established in space such as the Spitzer Space Telescope and the Herschel Space Observatory are primarily based on infrared radiations.
13. Art and Historic Restoration
The restoration of damaged or missing art pieces and historic components is generally based on the working of infrared sensors. The technique generally used for such purposes is known as infrared reflectography. It typically makes use of irradiation of infrared radiations on the surface of the target object. A portion of the incident radiations gets absorbed by the object, while some portion gets reflected back. The nature of the reflected radiations is recorded and examined to gain information about the original image. The infrared reflectography technique can also be used to verify the originality and authenticity of a art piece such as a portrait, a document, a decorative item, etc.
Why’d you have to end on number 13? Don’t ya know that’s bad luck, man?