Infrared: Difference between revisions
Added color swatch. (Sorry, Satan made me do it. I'll be good from now on. :) |
The_ansible (talk) added PDAs |
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'''Infrared''' radiation is [[light]] (i.e., [[electromagnetic radiation]]) of a wavelength longer than visible light, but shorter than [[microwave]] radiation. |
'''Infrared''' radiation is [[light]] (i.e., [[electromagnetic radiation]]) of a wavelength longer than visible light, but shorter than [[microwave]] radiation. |
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It is abbreviated as IR. |
It is abbreviated as IR. |
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The name means "below red" (from [[latin language|Latin]] ''infra'', "below"), |
The name means "below red" (from [[latin language|Latin]] ''infra'', "below"), |
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[[red]] being the [[color]] of visible light of longest wavelength. If your computer monitor is warm, the following patch should be coloured infrared: |
[[red]] being the [[color]] of visible light of longest wavelength. If your computer monitor is warm, the following patch should be coloured infrared: |
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<table align="center"> |
<table align="center"> |
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<tr><td bgcolor="#000000"><font color="#000000" size="+6"> |
<tr><td bgcolor="#000000"><font color="#000000" size="+6">██</font></td></tr> |
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</table> |
</table> |
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Often subdivided into near IR (NIR, 800 nm-2 μm wavelength), mid or intermediate IR (MIR or IIR, 2 - 30 μm) and far IR (FIR, 30 - 200 μm). However, these terms are not precise, and are use variously between different fields of study. |
Often subdivided into near IR (NIR, 800 nm-2 μm wavelength), mid or intermediate IR (MIR or IIR, 2 - 30 μm) and far IR (FIR, 30 - 200 μm). However, these terms are not precise, and are use variously between different fields of study. |
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Infrared radiation is often linked to [[heat]], since objects at room temperature or above will [[spontaneous emission|emit radiation]] mostly concentrated in the mid-infrared band (see [[black body]]). |
Infrared radiation is often linked to [[heat]], since objects at room temperature or above will [[spontaneous emission|emit radiation]] mostly concentrated in the mid-infrared band (see [[black body]]). |
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Although relatively harmless, overexposure to IR can cause damage to cells and is the cause of [[sunburn]] (commonly thought to be caused by [[ultraviolet|ultraviolet radiation]]). |
Although relatively harmless, overexposure to IR can cause damage to cells and is the cause of [[sunburn]] (commonly thought to be caused by [[ultraviolet|ultraviolet radiation]]). |
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'''Uses''' |
'''Uses''' |
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Infrared is used in [[night-vision]] equipment, when their is insufficient [[visible light]] to see an object. The radiation is detected and turned into an image on a screen, hotter objects showing up brighter, enabling the police and military to chase targets. |
Infrared is used in [[night-vision]] equipment, when their is insufficient [[visible light]] to see an object. The radiation is detected and turned into an image on a screen, hotter objects showing up brighter, enabling the police and military to chase targets. |
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A more common use of IR is in [[television]] remote controls. In this case it is used in preference to [[radio wave]]s because it does not interfere with the signal. |
A more common use of IR is in [[television]] remote controls. In this case it is used in preference to [[radio wave]]s because it does not interfere with the signal. |
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Another common use is for short-range communication among computer peripherals and [[personal digital assistants]]. |
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Revision as of 23:40, 16 November 2001
Infrared radiation is light (i.e., electromagnetic radiation) of a wavelength longer than visible light, but shorter than microwave radiation.
It is abbreviated as IR.
The name means "below red" (from Latin infra, "below"),
red being the color of visible light of longest wavelength. If your computer monitor is warm, the following patch should be coloured infrared:
| ██ |
Often subdivided into near IR (NIR, 800 nm-2 μm wavelength), mid or intermediate IR (MIR or IIR, 2 - 30 μm) and far IR (FIR, 30 - 200 μm). However, these terms are not precise, and are use variously between different fields of study.
Infrared radiation is often linked to heat, since objects at room temperature or above will emit radiation mostly concentrated in the mid-infrared band (see black body).
Although relatively harmless, overexposure to IR can cause damage to cells and is the cause of sunburn (commonly thought to be caused by ultraviolet radiation).
Uses
Infrared is used in night-vision equipment, when their is insufficient visible light to see an object. The radiation is detected and turned into an image on a screen, hotter objects showing up brighter, enabling the police and military to chase targets.
A more common use of IR is in television remote controls. In this case it is used in preference to radio waves because it does not interfere with the signal.
Another common use is for short-range communication among computer peripherals and personal digital assistants.