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0answers
16 views

Does anyone know of a paint/tape/plastic that blocks near IR radiation (<800nm) but not visible radiation? [closed]

Basically I'm looking for a material which blocks/reflects a light only in the NIR spectral range, if it also blocks UV that is no issue provided it is transparent to visible light.
3
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0answers
30 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 ...
2
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0answers
29 views

Infrared light absorption characteristics of vegetable oil [closed]

How much infrared light is absorbed by vegetable oil?
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1answer
34 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 ...
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2answers
29 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
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0answers
10 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
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1answer
32 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 ...
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0answers
9 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 ...
0
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0answers
25 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
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1answer
25 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
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0answers
22 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, ...
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5answers
2k 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
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1answer
71 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 ...
0
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2answers
166 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. ...
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2answers
584 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?
0
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0answers
25 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
23 views

Why would longer distance between collimated lenses improve coupling efficiency?

Im coupling 1550nm output from a single-mode lensed optical fiber to a standard SMF using a pair of collimating lenses, matched to the NA of the respective fibers. However, I find that by increasing ...
0
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0answers
21 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 ...
1
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1answer
91 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 ...
0
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1answer
60 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
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1answer
647 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
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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
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1answer
41 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
60 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 ...
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0answers
30 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 ...
3
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2answers
200 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 ...
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2answers
199 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 ...
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2answers
3k 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 ...
0
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1answer
271 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 ...
0
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1answer
64 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 ...
2
votes
1answer
346 views

What material would block (reflect, appear opaque) IR light 750-850nm range, but allow visible light to pass? [closed]

I'd like to find a material, ideally a plastic, that would prevent IR light from passing , but appear as transparent as possible to visible light. I've sampled some plascolite products and they work, ...
0
votes
1answer
60 views

How does the flow of photons (qty/s) vary across the spectrum? (In everyday life)

Humans see only a narrow band of light wavelengths. Many animals see much deeper into infrared. Maybe one clue to explain why we don't see IR naturally, has to do with the light intensity as a ...
2
votes
1answer
76 views

Short Laser pulse in near field bandwidth

Is there a way to create a short laser pulse that has, at least in the near field, a very narrow frequency range?
1
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2answers
77 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 ...
3
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1answer
318 views

Using infrared temperature sensor to measure water surface temperature

Can I use infrared temperature sensor (such as TS118-3) to measure water surface temperature? I'm afraid some effects such as reflection of infrared waves from water surface and blinking because of ...
3
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3answers
2k 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 ...
3
votes
2answers
2k views

Why human and most of vertebrates cannot see Near-Infrared light (720nm-1500nm)? [closed]

On daytime, the surface of Earth is illuminated abundantly by light of spectrum from 250nm-1500nm, that includes near-ultraviolet spectrum (250nm-380nm), visible spectrum (380nm-720nm) and ...
7
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3answers
10k 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 ...
3
votes
1answer
90 views

Is it possible to improve the efficacy of light bulbs with a semipermeable mirror? (The greenhouse bulb)

Let us imagine that there exists a material that reflects infrared radiation, but is transparent for visible light. Could we take an incandescent bulb and add this material to the inner surface of the ...
2
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2answers
73 views

Thermographic camera - show for visiting school children

Next week a group of pupils (12-14 years old) will visit my institute. I would like to teach them about infrared radiation. Do you have any suggestion what kind of simply and impressive experiments I ...
0
votes
1answer
202 views

Why do metal surfaces reflect thermal signature?

I recently borrowed a thermal camera from a friend and I tried to observe my palm print over a reflective metallic plate. When I looked at it through the camera, it reflected my thermal signature too. ...
2
votes
1answer
150 views

How long does it take plasma to radiate its heat?

Lets say we have 1 gram of plasma (Argon) at 1 million kelvin confined in a vacuum with electromagnets. If we keep the magnets on but shut down the device that heated the plasma, how long will it take ...
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3answers
213 views

How damaging is light? [closed]

On Surely You're Joking Mr Feynman, when talking about the Trinity test, the author states: the only thing that could really hurt your eyes (bright light can never hurt your eyes) is ultraviolet ...
1
vote
1answer
56 views

Why infrared absorption is a nonlinear technique?

I am looking for a good explanation and/or reference quotation explaining why infrared absorption technique is essentially nonlinear (eg. for carbon monoxide quantification). When using ...
2
votes
1answer
3k views

Why does glass absorb infrared light?

I was under the impression that glass was transparent to light with a wavelength above ultraviolet, but when playing with my latest toy, an infrared thermometer which brought up a question I asked ...
15
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2answers
2k views

Why does my infrared thermometer say the sky is at -2 °C?

I just got myself an infrared thermometer. I wouldn't have been able to predict what temperature it would give me when pointing at the sky, but it turned out to be -2 °C the first time I measured, and ...
1
vote
1answer
165 views

What does adding a visible light blocking IR filter do with heat?

Lets say I have a strong halogen light source which has a lot of IR radiation (e.g. a construction lamp). If I change the transparent front glass from the enclosure with a IR filter that blocks ...
8
votes
2answers
130 views

Can the hot combustion products from a large flame be in “non-local thermal equilibrium”

Question: Does it take some time for the hot combustion products from a flame to reach local thermodynamical equilibrium (i.e. for the energy state populations to follow the Boltzmann distribution)? ...
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1answer
36 views

Rate of radiation of infra-red ray from a hot body?

I have the equation $\frac{dE}{dt}=a(\tau^4-\tau_s^4)$ however I can't find anywhere what E is supposed to be. It is not pointed out anywhere in the text and what is confusing is that in engineering E ...
0
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2answers
154 views

How camera flash can send information

Nikon have CLS a system that allow to trigger one flash with other flash. I don't know how exactly it work from user point of view, I think that one flash (in command mode) can send information like ...