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12
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2answers
2k views

How can IR cameras see things colder than the camera?

I’ve read that only cold-blooded animals develop IR vision to spot warm prey because a mammal would blind himself with his own heat and not be able to see anything. But I’ve seen a FLIR camera, ...
2
votes
1answer
27 views

How does infrared light behave through water?

I have a project involving the detection of the presence of water in a cylindrical transparent plastic container (diameter=25cm) And I cannot put any device inside, so I was thinking of using and IR ...
1
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1answer
34 views

How / why do infrared thermometers work?

How can reading the intensity of infrared radiation coming from an object let you calculate its temperature? Could any wavelength be used to measure temperature - why infrared, and not, for instance,...
2
votes
1answer
83 views

Why infrared absorption is a nonlinear technique?

I am looking for a good explanation explaining why infrared absorption technique is essentially nonlinear (eg. for carbon monoxide quantification). When using UV/visible/near-IR absorption technique, ...
1
vote
1answer
25 views

Radiation-Glossy Black vs Matte White

Well, studying the chapter Heat I know that a matte black body radiates heat more than a glossy white one but can anyone give me an answer about what happens when its a glossy black body and a dull ...
0
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0answers
16 views

Focal length value for infrared camera

I always thought that the 5 mega pixel camera attached to my Android tablet wasn't worthy of seeing the infrared. But I was wrong! The infrared led protruding from my circuit happily shows up it's ...
3
votes
3answers
56 views

Does visible light heat things up?

During a sunny day the walls of my house warm up (no surprise). My question: how much of this warming up (if any) comes from visible light? I associate infrared with thermal energy. If my house was ...
2
votes
2answers
159 views

Can you use infra-red goggles (or similar principle) to see through mist and fog?

As per title really... fog is obviously quite opaque to visible light yet transparent to radio waves. What is the range of frequencies at which fog is opaque, and is either end of this range at a ...
3
votes
2answers
286 views

Why is infrared radiation associated with heat?

I am little confused with infrared radiation. I understand that when an object is hotter, it radiates electromagnetic waves of a bigger frequency and this waves are also more energetic, that is why ...
0
votes
2answers
64 views

Do homonuclear diatomic molecules interact with infrared light?

A molecule will appear on IR spectra if its dipole moment changes during vibration. Due to symmetry, the dipole moment of homonuclear diatomic molecules ($\mathrm{H_2, N_2, O_2, F_2, \dots}$) is zero. ...
3
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3answers
3k views

Do infrared lamps provide more heat than incandescent lamps?

Infrared lamps seem to be used in situations where you want to produce heat without producing (as much) light. But incandescent bulbs also produce heat. Why not just use incandescent bulbs? My ...
7
votes
4answers
16k views

What common materials absorb most infrared light?

I'm competing in a simple robotics competition where most of the participants use reflected infrared light to detect their opponent. I'd like to make my own robot as difficult to see as possible. What ...
4
votes
1answer
426 views

Why 8–15 µm is considered “thermal infrared” if typical room temperature kT is 48 µm?

According to Wikipedia: Long-wavelength infrared (8–15 µm, 20–37 THz, 83–155 meV): The "thermal imaging" region, in which sensors can obtain a completely passive image of objects only slightly ...
1
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1answer
29 views

When thermal IR gets reflected from an object, does it change its wavelength (frequency)

I'm working with thermal infrared (IR) cameras to detect human thermal radiation. I notice I can easily distinguish non-human objects throughout the camera's field of view, though all are at same room ...
0
votes
1answer
36 views

Why does Raman activity depend on polarizability?

Raman spectroscopy essentially records photoluminescence: (source) and a molecule is considered to be Raman active when there is a change of polarizability $\alpha$ (where $\mathbf{P}=\alpha \mathbf{...
0
votes
3answers
62 views

Do white light generated by light bulb also have significant Infrared intensity?

I am planning to obtain near infrared light for a project. Instead of producing the infrared myself, I thought it might be easier to use something inexpensive and commercially available. That's why I ...
0
votes
0answers
24 views

How thermographic camera works?

I understand the basic principle, bodies with higher temperature than 0K produce infrared radiation emission, a thermographic camera detects that radiation. However, my question is how that radiation/...
3
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5answers
12k views

How does Infrared Relate to heat?

I never understood the relationship between Infrared and Heat. Is IR emitted when heat is generated, is heat generated when IR is made, and how do the two relate?
0
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0answers
12 views

System of two perfect isolated bodies and infrared death

What is the theory about a system of two bodies, which is perfect isolated from the environment? Take it as a Gedankenexperiment, where the two bodies are not perfect reflectors but the isolating ...
7
votes
3answers
3k views

Why do moving particles emit thermal radiation?

While answering another question about heat in an atom, the discussion in the comments led to the question of how heat is related to thermal radiation picked up by infrared cameras. The answer is that ...
0
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2answers
671 views

Thermal Imaging reflection?

I was viewing a youtube video that was about thermal imaging and saw something that caused me to ponder but I couldn't figure out an answer and the one assumption I have I don't know if it's correct. ...
3
votes
0answers
49 views

What paint absorbed the most infrared light? [closed]

Is Parents recently installed drainage gutters on the back part of there house. The problem is they did not take into account the location of their security cameras. So now at night the infrared ...
0
votes
1answer
64 views

Calculate spectral radiance at defined wavelength given radiant power

I am struggling with what I think is actually a simple problem. I have an LED that emits infrared light (950 nm). It is part of a sensor system. The manufacturer claims it has a radiant power of 3000 ...
2
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0answers
41 views
1
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2answers
51 views

Materials that effectively block IR partially

I would like to know what are the effective materials that can partially block IR (but not fully) of wavelength 8-14 um. My idea is to blur the images taken from a thermal camera by adding this piece ...
0
votes
0answers
17 views

Radiation heat loss and reuse

When the human body lose radiation heat rays, is there a way we can pick it up and collect it? And then use it over again by fex. using a heat exchanger and a device that can emit them (rays) back out ...
0
votes
1answer
43 views

Infrared light and heat

I know that mid wave IR, long wave IR, and far IR are all infrared light that we feel as heat. Often, even when it is cold and windy, if I face the sun in a sunny spot it feels like it is 80 degrees F ...
2
votes
6answers
20k views

Why does a human body only emit infra red radiation and not other types of electromagnetic radiation?

What causes humans to emit infra red radiation and why don't we also emit other types of electromagnetic radiation such as ultra violet or microwave? Sunlight contains UV and our body takes it in, but ...
7
votes
2answers
3k views

Why does an infrared thermometer display very low temperature when being directed to the outer air?

I'm toying with an infrared thermometer - one which you point onto an object, press the button and it instantly measures the temperature by estimating the infrared radiation from the object. It shows ...
0
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0answers
14 views

What's the contribution from nuclei and electrons in molecular infrared absorption process?

I'm very glad to post the first question on this StackExchange forum. It's wonderful to discuss the sientific problems with experts, researchers, teachers and students on the website. Even my question ...
0
votes
0answers
26 views

How long does it take for space dust to stop irradiating energy?

I heard that space dust is detectable because it irradiates on the infrared part of the spectrum? Does this happen forever? Won't it stop after some millions of years? Does it have to irradiate until ...
0
votes
1answer
27 views

How to configure two infrared light to produce two different intensity

I have two infrared illuminators that have the same properties (same wavelength, same number of leds, same angles, same max voltage and amperage). suppose that these illuminators are attached at the ...
2
votes
0answers
27 views

Penetration depth of thermal IR into building and insulation materials

What are the values of the penetration depth (or the attenuation coefficient) of thermal infrared radiation (say, 5-20 $\mu$m wavelength) into common building and insulation materials (brick, stone, ...
8
votes
5answers
5k views

Why can't we see infrared light?

While explaining to my nephew about the physics of light, I told him we cannot see infrared color, and he kicked back with a very simple question: why can't we see it? I could not tell him. Is the ...
0
votes
1answer
154 views

define narrow band and broadband in Infrared light source

I have an infrared transmitter where the specification sheet says Broadband Emission from 400 to 2200 nm Does this mean it will transmit all mixed wavelength of infrared light between 400 to ...
-2
votes
2answers
2k views

Why we can't see light emitted from TV remote while a camera can?

If we try to see light emitted from tv remote we can see this. while if we try same in camera we are able to see this. Why?
3
votes
2answers
300 views

How does an infrared thermometer actually calculate temperature?

I am slightly confused about infrared radiation and the equations related to it. $P = A \epsilon \sigma T^4$ (1) and $B_{\lambda}(\lambda,T) = \frac{2hc^2}{\lambda^5} \frac{1}{e^{\frac{hc}{\lambda ...
0
votes
0answers
30 views

Can near-infrared spectroscopy distinguish between various metals?

Can near-infrared spectroscopy be used to distinguish metals from another? If not, why not?
0
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0answers
30 views

Optimal wavelength for low IR attenuation under normal atmospheric conditions?

I can't find any good data about the transmit attenuation of infrared light in the atmosphere transmitted horizontally (there is a bunch of stuff detailing penetration of radiation from space, but ...
0
votes
1answer
83 views

Can infrared lasers still do damage to things if they are powerful enough?

So I get that infrared light is not visible to the human eye without some sort of device to assist in helping you see it, but I was just wondering how that plays into things like lasers. I know you ...
3
votes
1answer
1k views

Why infrared light waves is visible through camera? [duplicate]

For example We know that some television manufacturers have the limited IR-based remotes which cannot be seen by our eyes directly but while playing when I just put my camera in front of my TV remote ...
0
votes
0answers
33 views

What is source of Infrared Radiation from some solid object? [duplicate]

I use a Fluke infrared temperature measurement meter for various applications. I have not thought too much about the source of that infrared radiation until recently. Assume some solid with maybe a ...
0
votes
1answer
44 views

Can high-power LEDs remotely control a whole room? [closed]

Let's say I have 4 appliances in rectangular based room of about 60 square meters with white walls. The appliances are using infrared receivers with a filter of 38 kHz. Would it be possible to apply ...
2
votes
1answer
67 views

Explaining William Herschels Infrared Discovery

First post, and probably a very simple answer that I'm missing, but here goes. Herschel found that red light warmed a thermometer more than blue light, and consequently that the region beyond the red ...
1
vote
0answers
31 views

How can we detect the property of matter by using mechanical waves or IR or any other way

First of all, I am in high school[to tell that I don't know much physics]. And the second thing is that, I am not sure whether this question is specifically related to physics. What I want to ...
1
vote
2answers
296 views

Does a source emitting visible light also emit infrared, microwave and radio waves?

I have a bulb which is hot enough to emit visible light and obviously it's hot enough to emit radiation which lies before the visible light temperature i.e. radio waves, microwaves, and infrared light....
5
votes
2answers
4k views

Why do we use microwaves in microwave oven?

We know that any object above absolute zero emits electromagnetic radiation. So hotter the object shorter the wavelengths. In the electromagnetic radiation spectrum radio waves has the longest then ...
1
vote
1answer
448 views

Does sunlight contain 940nm wavelength light?

Apologies if this has an obvious answer, my knowledge of this area is very limited. I am attempting to produce a setup that will allow me to illuminate objects in 940nm wavelength infrared light, and ...
1
vote
2answers
87 views

Is there a portable method of preventing all IR radiation from being emitted?

Me and some friends were recently disuccing "How cool it would be to be invisible", from a military viewpoint, I said that Camouflage, when done correctly, works surprisingly well, so invisibility was ...
0
votes
1answer
95 views

Can an aluminized blanket hide a person from thermal cameras? [duplicate]

Well, if the person is wrapped tightly I expect the answer is "no", but could an aluminized loose "cloak" hide a person from thermal imaging cameras by reflecting the cold surroundings? Or, if the ...