What is Infrared Radiation?
This information was developed at the Infrared Processing and Analysis Center at California Institute of Technology. Our eyes are detectors which are designed to detect visible light waves (or visible radiation). Visible light is one of the few types of radiation that can penetrate our atmosphere and be detected on the Earth's surface. There are also forms of light (or radiation) which we cannot see. Actually we can only see a very small part of the entire range of radiation called the * electromagnetic spectrum. The electromagnetic spectrum includes gamma rays, X-rays, ultraviolet, visible, infrared, microwaves, and radio waves (Figure 2). The only difference between these different types of radiation is their wavelength or frequency. Wavelength increases and frequency (as well as energy and temperature) decreases from gamma rays to radio waves. All of these forms of radiation travel at the speed of light (186,000 miles or 300,000,000 meters per second in a vacuum). In addition to visible light, radio, some infrared and a very small amount of ultraviolet radiation also reaches the Earth's surface from space. Fortunately for us, our atmosphere blocks out the rest, much of which is very hazardous if not deadly for life on Earth.
Infrared radiation lies between the visible and microwave portions of the electromagnetic spectrum. Thus infrared waves have wavelengths longer than visible and shorter than microwaves and have frequencies which are lower than visible and higher than microwaves. Near infrared refers to the part of the infrared spectrum that is closest to visible light and far infrared refers to the part that is closer to the microwave region.
Figure 2. Electromagnetic spectrum.
to penetrate – походить сквозь, пронизывать
wavelength or frequency – длина волны или частотность
Answer the questions:
Can “light waves” and “visible radiation” be considered as synonyms?
What is visible light?
What part of the entire range of radiation can we see?
What does the electromagnetic spectrum include?
What is the difference between different types of radiation?
What is the speed of radiation traveling?
Does ultraviolet radiation reach the Earth's surface from space?
What Exactly is Infrared Heat?
Infrared heating is the transfer of thermal energy in the form of electromagnetic waves. True infrared heat should have one common characteristic: that the transfer of heat is emitted or radiated from the heated object or substance. The source emits radiation at a peak wavelength towards an object. The object can absorb the radiation at some wavelength, reflect radiation at other wavelengths, and re-radiate wavelengths. It is the absorbed radiation that creates the heat within the object.
Types of Electric Infrared Heaters
Some of the types of industrial electric infrared heaters are ceramic elements, quartz tubes and lamps, quartz emitters, flat faced quartz, glass and metal panel heaters, metal sheathed tubular (calrods) and open coil wire elements.
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