Infrared radiation is electromagnetic radiation, located on the border with the red spectrum of visible light. The human eye is not able to see this spectrum, but we feel it on our skin as heat. When exposed to infrared rays, objects heat up. The shorter the wavelength of infrared radiation, the stronger the thermal effect will be.
According to the International Organization for Standardization (ISO), infrared radiation is divided into three ranges: near, mid and far. In medicine, pulsed infrared LED therapy (LEDT) uses only near-infrared wavelengths because it does not scatter at the surface of the skin and penetrates subcutaneous structures.
The spectrum of near-infrared radiation is limited from 740 to 1400 nm, but with increasing wavelength, the ability of the rays to penetrate tissue decreases due to the absorption of photons by water. “RIKTA” devices use infrared diodes with a wavelength in the range of 860-960 nm and an average power of 60 mW (+/- 30).
The radiation of infrared rays is not as deep as laser radiation, but it has a wider range of effects. Phototherapy has been shown to accelerate wound healing, reduce inflammation and relieve pain by acting on subcutaneous tissue and promoting cell proliferation and adhesion in tissue.
LEDT intensively promotes heating of the tissue of surface structures, improves microcirculation, stimulates cell regeneration, helps reduce the inflammatory process and restore the epithelium.
EFFECTIVENESS OF INFRARED RADIATION IN TREATING HUMANS
LEDT is used as an addition to low-intensity laser therapy with RIKTA devices and has therapeutic and preventive effects.
Exposure to infrared radiation helps accelerate metabolic processes in cells, activates regenerative mechanisms and improves blood supply. Infrared radiation has a complex effect, it has the following effects on the body:
increasing the diameter of blood vessels and improving blood circulation;
activation of cellular immunity;
relieving tissue swelling and inflammation;
cupping pain syndromes;
improvement of metabolism;
relieving emotional stress;
restoration of water-salt balance;
normalization of hormonal levels.
When exposed to the skin, infrared rays irritate receptors, transmitting a signal to the brain. The central nervous system reflexively responds by stimulating general metabolism and increasing overall immunity.
The hormonal response promotes the expansion of the lumen of microcirculatory growth vessels, improving blood flow. This leads to normalization blood pressure, better transport of oxygen to organs and tissues.
SAFETY
Despite the benefits of pulsed infrared LED therapy, exposure to infrared radiation must be dosed. Uncontrolled irradiation can lead to burns, redness of the skin, and overheating of tissues.
The number and duration of procedures, frequency and area of infrared radiation, as well as other treatment features should be prescribed by a specialist.
APPLICATION OF INFRARED RADIATION
LEDT therapy has shown high effectiveness in the treatment of various diseases: pneumonia, influenza, sore throat, bronchial asthma, vasculitis, bedsores, varicose veins veins, heart disease, frostbite and burns, some forms of dermatitis, peripheral nervous system and malignant skin tumors.
Infrared radiation, along with electromagnetic and laser radiation, has a general strengthening effect and helps in the treatment and prevention of many diseases. The “RIKTA” device combines multi-component radiation and allows you to achieve maximum effect in short term. You can buy an infrared radiation device at.
Since the devices appeared on the market infrared heating slowly but surely gaining more and more popularity. The scope of their application is quite wide - from ordinary residential premises to high-rise industrial buildings. Naturally, the design and operating principle of an infrared heater is of considerable interest. We bring to your attention this article, where all questions regarding the operation of these devices will be discussed in detail.
Infrared heater: how does it work?
To get an idea of how infrared heating devices operate, let’s first understand the ways in which thermal energy can be transmitted in a room. There are only two of them:
- convection: any object whose temperature is higher than the surrounding air exchanges heat with it directly. The air, heated by this object, loses density and mass, due to which it rushes upward, displaced by a heavier cold flow. Thus, the circulation of air masses of different temperatures begins in the space of the room.
- radiant heat: a surface having a temperature of more than 60 ºС begins to intensively emit electromagnetic waves in the range of 0.75-100 microns, carrying thermal energy. This is the basis for the work of infrared heaters, whose heating elements emit such waves.
The most comfortable range of infrared radiation for humans is from 5.6 to 100 microns, within which most infrared heaters operate. An exception is long-range devices installed on the ceilings of industrial buildings. They emit in the medium (2.5-5.6 µm) and short (0.75-2.5 µm) ranges and are located at a distance from the target of 3-6 m and 6-12 m, respectively. It is unacceptable to use such emitters in residential buildings.
When infrared rays hit surfaces within visibility, they increase their temperature. After this, the principle of convection comes into effect, heat begins to be transferred from the surfaces to the air of the room. Such heating is more uniform than during the operation of traditional convective systems, which is reflected in the figure:
Heater device
Before considering the design of an infrared heater, we note that these devices are produced in 2 types:
electric: they use heating elements various types: carbon spirals, tubular heating elements, halogen lamps and film micathermic panels.
gas: here IR rays are emitted by a heated ceramic element.
We will consider the design of the device using the example of a ceiling-mounted long-wave heater powered from the mains. In it, the role of a heating element is played by an aluminum plate with a built-in heating element of a special design. An anodized coating is applied to the surface of the plate, which improves the heat transfer of the surface. WITH reverse side reflector and layer installed thermal insulation material. The diagram below shows the design of ceiling heaters:
1 – metal body; 2 – ceiling mounting brackets; 3 – heating element; 4 – radiating plate made of aluminum; 5 – layer of thermal insulation with a reflector.
Others electrical appliances infrared heating with other types of heating elements are structurally not much different from pendant-type radiators. The only significant difference between them is the method of control. Wall-mounted and floor-mounted IR heaters have a built-in control unit with a thermostat and a tilt sensor. For ceiling-mounted devices, this unit is a remote unit mounted on the wall; it can control several devices simultaneously.
It must be said that the principle of operation of a gas infrared heater is similar to an electric one, only thermal energy is obtained in different ways.
In a gas appliance heating element serves as a ceramic plate, whose temperature can reach 900 ºС depending on the settings. The plate warms up gas burner, located in the end part of the housing, as shown in the diagram:
What is the secret of popularity?
Manufacturers declare the following advantages of infrared heaters:
- high efficiency and cost-effectiveness;
- absence of rotating parts and noise;
- stands out soft warmth, which does not cause a deterioration in a person’s well-being;
- simple installation and connection.
As a rule, these are general phrases; something similar can be found in descriptions of oil radiators or wall convectors. They do not answer the question: why are devices so attractive to users in real life? It turns out that everything is simple, the operation of a ceiling infrared heater, like a wall-mounted one, is possible in non-insulated buildings, in drafts and even on the street. The main thing is to be within the range of infrared radiation.
A device emitting infrared waves will create a zone comfortable warmth in front of you, leaving the rest of the room unnoticed. It will warm up after a few hours from heated objects. But the fact remains: in a room where 1 kW of heat is needed for heating, people install a 500 W infrared heater so that the radiant heat is distributed as widely as possible. It creates an illusion good heating, although in fact the temperature in the room remains dog-like, the laws of physics cannot be deceived.
If heating a room requires 1 kW of heat, then the infrared emitters should be of exactly this power, then there will be no illusions, a comfortable temperature will quickly be established in the entire room.
The devices also have other disadvantages. For example, the design of an infrared heater in a suspended design implies a wasteful consumption of about 10% of the heat accumulating under the ceiling. This is a convective transfer of energy from the heated body of the device to the surrounding air, which remains there, under the ceiling. Wall heaters interfere with operation various items, carbon and halogen devices irritate with their bright light, and micathermic ones - with a high price.
Conclusion
In general, infrared electric and gas heaters are perfect products and can heat private homes well. The main thing when buying is not to follow the lead of the sellers and choose a device of the required power, and then arrange it at home in the optimal way.
Infrared waves are not visible to the human eye. However, in essence, they are the same electromagnetic waves as visible light, and propagate in space according to the same laws. Therefore, such radiation can be emitted by a special illuminator and then captured by an optical device in which the converter turns invisible infrared waves into visible light.
An optical-electronic converter is used to convert infrared radiation into visible light. It converts infrared light into a stream of electrons, and the electrons, bombarding a special screen, cause it to glow in the visible range. The light emanating from the OEP is directed directly into the observer’s eye and recorded by a camera or video camera.
What should you pay attention to when selecting equipment for observation in the infrared range?
The quality of the image (brightness, contrast, sharpness, target detection range against the background of the landscape) depends both on the quality of the illuminator and on the NVD (generation of the image intensifier, quality of the optics). In addition to image clarity, important factors when choosing a device for observation in the infrared range are:
- Weight and dimensions of the device;
- Reliable operation, durability;
- Device power consumption, type of power source;
- Protection of the device from moisture or dirt getting inside, resistance to shock and recoil;
- Price.
The choice should be made taking into account the specific objectives and purchase budget. Of course, for observation while hunting, you should look for a more compact and lightweight device, designed to withstand the load caused by the recoil of the weapon. And to ensure the protection of the territory, you can choose larger structures that have the ability to operate continuously for a long time.
presented on the Russian market
- . An observation device that visualizes radiation from the infrared part of the spectrum. The device is designed to operate using an infrared laser (solid-state or LED) with a wavelength of about 350...2000 nanometers as an emitter. The S-1+ photocathode used in the design allows you to see a clear image when observing a target at any distance within the capabilities of the device.
The device is easy to use. Compact dimensions and low weight allow you to observe without fatigue for a long time. The device has a comfortable handle. It can also be attached to a helmet-mask, freeing your hands for work. The device can withstand temperatures from -10ºC to +40ºC. Power supply - “little finger” 1.5-volt battery.
- . The device is capable of converting radiation from the infrared part of the spectrum with a wavelength from 320 to 1700 nanometers into visible light. Since it weighs only 250g, it can be used for long-term observation without causing hand fatigue. The ergonomic handle contributes to the comfort of observation. For more convenient observation, the device can be attached to a helmet mask and free your hands.
A more serious modification has also been developed for this model. It has a greater range of sensitivity to infrared radiation. The upper limit of the range is 2000 nanometers.
- . The camera is capable of detecting infrared radiation, which has a wavelength from 400 to 1700 nm. It can be used either directly for observation or attached to a microscope and for infrared microscopy, spectrography, forensic studies and other research work.
The camera's silicon CCD sensor has high sensitivity. It also implements the principle of electronic radiation amplification. The camera is powered by 4 AA batteries. There is also a built-in charger. Network adapter allows you to take 12V from a household power supply, so you can work with the camera for a long time and in a comfortable environment. The product comes with a tripod and a carrying bag.
- translates to visible radiation infrared waves with a wavelength of 350 - 1700 nm. In this design, an image intensifier with extended sensitivity is combined with an SSD camera. Thanks to the 4-inch LCD display, you can quickly monitor, and the video output allows you to record information on external media. The camera will be indispensable in infrared microscopy and forensic research. Power is supplied from 4 AA batteries. The camera's continuous operation time on one set of batteries is about 1.5 hours.
- Helmet-mask FM-1. This convenient accessory helps free your hands when working with SM-3R and Abris-M infrared surveillance devices. The mask mechanism has two fixed positions. In this case, it is possible to attach the device on the right or left side, depending on the preferences of the observer. The position of the fixed device is also adjustable in three directions.
As you can see, today there are many devices on store shelves that allow you to monitor and record information in the near-infrared range. In this variety, any, even the most demanding buyer will find an option that suits him in terms of capabilities and cost.
Light is one of the main conditions for the life of earthly organisms. Many biological processes can occur only under the influence of infrared radiation.
Light as a healing factor was used by ancient doctors of Greece and Egypt. In the 20th century, light therapy began to develop as part of official medicine. However, it should be noted that infrared radiation is not a panacea.
What is infrared radiation
The branch of physiotherapy that studies the effect of light waves on the body was called phototherapy. It has been proven that waves of different ranges affect the body in different layers and levels, with infrared radiation having the greatest penetration depth, and ultraviolet light having the most superficial effect.
Infrared radiation has a wavelength from 780 to 10,000 nm (1 mm). In physiotherapy, as a rule, waves ranging from 780 to 1400 nm are used, i.e. short, penetrating into tissues to a depth of about 3 centimeters.
Therapeutic effects
Under the influence of infrared radiation, heat is generated in tissues, physical and chemical reactions are accelerated, tissue repair and regeneration processes are stimulated, the vascular network expands, blood flow accelerates, cell growth increases, biologically active substances are produced, leukocytes are directed to the lesion, etc.
Improving blood supply and expanding the lumen of blood vessels leads to a decrease in blood pressure, psycho-emotional and physical stress, muscle relaxation, lifting your mood, improving sleep and feeling comfortable.
In addition to the above, infrared radiation has an anti-inflammatory effect, stimulates the immune system and helps the body fight infectious agents.
Thus, infrared therapy has the following properties:
- anti-inflammatory;
- antispasmodic;
- trophic;
- stimulating blood flow;
- awakening the reserve functions of the body;
- detoxification;
- pronounced biostimulating effect.
Speaking about light therapy, one cannot help but recall the founder of this branch of physiotherapy, the Danish physician and scientist Niels Ryberg Finsen, who received the Nobel Prize for the successful use of concentrated light radiation in the treatment of various diseases. With the help of his works, it became possible to expand the possibilities of light therapy.
Techniques
Infrared therapy comes in two types: local and general.
With local exposure, a specific part of the patient’s body is exposed to radiation, and with general exposure, his entire body is exposed.
Procedures are carried out 1 or 2 times a day, the duration of one session is from 15 to 30 minutes. The course of treatment consists of 5-20 procedures.
You need to know that during exposure to the facial area, the eyes must be protected with special glasses, cardboard covers, cotton wool and other methods.
After the session, erythema (redness) with unclear contours remains on the skin, which disappears without a trace an hour after the end of the procedure.
Indications
The main indications for infrared ray therapy are:
- degenerative-dystrophic diseases of the musculoskeletal system;
- consequences of injuries, joint pathologies, contractures, infiltrates;
- chronic and subacute inflammatory processes, slow-healing wounds;
- neuritis, neuralgia, myalgia;
- dermatitis, dermatoses, neurodermatitis, consequences of frostbite and burns, scars, trophic ulcers;
- some diseases of the ENT organs;
- eye pathologies.
Contraindications
If you have the following diseases and conditions, treatment with infrared radiation should be avoided:
- purulent processes without outflow of contents;
- exacerbation of chronic diseases;
- presence of neoplasms;
- active form of tuberculosis;
- tendency to bleed;
- blood diseases;
- pregnancy;
- individual intolerance to the method.
Devices
Today it is possible to take light therapy procedures both in medical institutions and at home. For this purpose there is large selection stationary and portable devices.
For treatment at home, portable devices are used that do not require special conditions of use.
Despite this, before starting self-medication, it is necessary to consult with a physiotherapist to determine the possible risks of prescribing the treatment method in question, as well as choosing a specific technique for each specific case.
The doctor will describe the treatment method, which will indicate which area needs to be treated, what gap between the device and the skin needs to be maintained, the intensity of the effect, the time of the treatment session and the number of procedures per course of physiotherapy.
Combination of therapeutic factors
Infrared therapy can be supplemented on the same day the following types physiotherapy:
- electrotherapy (four-chamber galvanic bath, amplipulse therapy, diadynamic therapy, electrosleep, franklinization, darsonvalization and ultratonotherapy);
- magnetic therapy;
- ultrasound therapy;
- laser therapy;
The combination of physical factors enhances the therapeutic effect and the body’s response to the procedure, reduces the duration of therapy and accelerates the patient’s recovery.
Should not be combined in one day:
- infrared therapy and ultraviolet irradiation;
- galvanization and electrophoresis.
The following are not performed on the same day as infrared therapy:
- inductotherapy;
- UHF therapy;
- decimeter and centimeter therapy;
- healing souls;
- paraffin treatment;
- mud therapy;
- therapeutic baths, including underwater massage and spinal traction.
These methods have a pronounced irritating effect on the body and can harm the patient’s health.
A wide range of diseases are treated using infrared radiation. The procedure is often so simple that therapeutic measures can be carried out at home. Consulting a doctor about contraindications and combinations of treatment factors will help achieve good results.
Video on the topic “Infrared therapy”
IR sub-bands:
- Near IR (abbreviated as NIR): 0.78 - 1 µm;
- Short wavelength IR (abbreviated SWIR): 1 - 3 µm;
- Medium wavelength IR (abbreviated as MWIR): 3 - 6 µm;
- Long wavelength IR (abbreviated LWIR): 6 - 15 µm;
- Very long wavelength IR (abbreviated VLWIR): 15 - 1000 microns.
The infrared spectral range of 0.78 - 3 microns is used in fiber-optic communication lines (short for fiber-optic communication line), external monitoring devices for objects and equipment for chemical analysis. In turn, all wavelengths from 2 microns to 5 microns are used in pyrometers and gas analyzers that monitor the level of pollution in a specific environment. The 3 - 5 µm interval is more suitable for systems that record images of objects with high own temperature or in applications where the requirement for contrast is higher than for sensitivity. The spectral range 8 - 15 microns, which is very popular for special applications, is mainly used where it is necessary to see and recognize any objects located in the fog.
All IR devices are designed in accordance with the IR transmittance schedule, which is given below.
There are two types of IR detectors:
- Photonic. Sensitive elements consist of semiconductors of various types, and can also include various metals in their structure; the principle of their operation is based on the absorption of photons by charge carriers, as a result of which they change electrical parameters sensitive area, namely: change in resistance, occurrence of a potential difference, photocurrent, etc. These changes can be recorded by measuring circuits formed on the substrate where the sensor itself is located. The sensors have high sensitivity and high response speed.
- Thermal. IR radiation is absorbed by the sensitive area of the sensor, heating it to a certain temperature, which leads to a change in physical parameters. These deviations can be recorded by measuring circuits made directly on the same substrate as the photosensitive area. The types of sensors described above have high inertia, significant response time and relatively low sensitivity in comparison with photon detectors.
Based on the type of semiconductor used, sensors are divided into:
- Own(undoped semiconductor with an equal concentration of holes and electrons).
- Impurity(doped n- or p-type semiconductor).
The main material of all photosensitive sensors is silicon or germanium, which can be doped with various impurities of boron, arsenic, gallium, etc. An impurity photosensitive sensor is similar to its own detector, with the only difference being that carriers from donor and acceptor levels can move into the conduction band, overcoming more low energy barrier, as a result of which this detector can operate with shorter wavelengths than its own.
Types of detector designs:
Under the influence of IR radiation, a photovoltaic effect occurs in the electron-hole transition: photons with an energy exceeding the band gap are absorbed by electrons, as a result of which they occupy places in the conduction band, thereby contributing to the emergence of a photocurrent. The detector can be made on the basis of both an impurity and an intrinsic semiconductor.
Photoresist. The sensitive element of the sensor is a semiconductor; the operating principle of this sensor is based on the effect of changing the resistance of a conductive material under the influence of IR radiation. Free charge carriers generated by photons in the sensitive region lead to a decrease in its resistance. The sensor can be made on the basis of both an impurity and an intrinsic semiconductor.
Photoemissive, also known as a “free carrier detector” or on a Schottky barrier.; To eliminate the need for deep cooling of impurity semiconductors, and in some cases to achieve sensitivity in the longer wavelength range, there is a third type of detector called photoemission detectors. In this type of sensor, a metal or metal-silicon structure covers dopant silicon. A free electron, which is formed as a result of interaction with a photon, enters the silicon from the conductor. The advantage of such a detector is that the response does not depend on the characteristics of the semiconductor.
Quantum well photodetector. The operating principle is similar to impurity detectors, in which impurities are used to change the structure of the bandgap. But in this type of detector, impurities are concentrated in microscopic regions where the band gap is significantly narrowed. The “well” formed in this way is called quantum. Registration of photons occurs due to the absorption and formation of charges in the quantum well, which are then drawn out by the field to another area. Such a detector is much more sensitive compared to other types, since an entire quantum well is not a single impurity atom, but from ten to one hundred atoms per unit area. Thanks to this, we can talk about a fairly high effective absorption area.
Thermocouple. The main element of this device is a contact pair of two metals with different work functions, resulting in a potential difference at the boundary. This voltage is proportional to the contact temperature.
Pyroelectric detectors made using pyroelectric materials and the operating principle of which is based on the appearance of a charge in the pyroelectric when a heat flow passes through it.
Microbeam detectors. It consists of a microbeam and a conductive base, which act as capacitor plates; the microbeam is formed from two tightly connected metal parts, having different coefficients of thermal expansion. When heated, the beam bends and changes the capacity of the structure.
Bolometers (Thermistors) consist of a thermoresistive material; the operating principle of this sensor is based on the absorption of IR radiation by the material of the sensitive element, which leads to an increase in its temperature, which in turn causes a change in electrical resistance. There are two ways to obtain information: measuring the current flowing in a sensitive area at a constant voltage and measuring voltage at a constant current.
Basic parameters
Sensitivity- the ratio of the change in electrical quantity at the output of the radiation receiver caused by the radiation incident on it, to quantitative characteristics this radiation. V/lk-s.
Integral sensitivity- sensitivity to non-monochromatic radiation of a given spectral composition. Measured in A/lm.
Spectral sensitivity- dependence of sensitivity on radiation wavelength.
Detection ability- the reciprocal value of the minimum radiation flux that causes a signal at the output equal to its own noise. It is inversely proportional square root from the area of the radiation receiver. Measured in 1/W.
Specific detection ability- Detection ability multiplied by the square root of the product of a frequency band of 1 Hz and an area of 1 cm 2. Measured in cm*Hz 1/2/W.
Response time- time required to establish an output signal corresponding to the input effect. Measured in milliseconds.
Operating temperature- maximum sensor temperature and environment, in which the sensor is able to correctly perform its functions. Measured in °C.
Application:
- Space surveillance systems;
- ICBM launch detection system;
- In non-contact thermometers;
- In motion sensors;
- In IR spectrometers;
- In night vision devices;
- In homing heads.