What is Ir: Definition and 229 Discussions

As far as I know, in most of metals, IR radiation is reflected almost entirely and is not absorbed by metals. How does a metal become warmed under IR radiation? or does reflection, on its own, can warm up a metal?

I've been reading up on Fourier Transform Infrared Spectroscopy and the Michelson Interferometer. My main sources are "Principles of Instrumental Analysis" by Skoog etc and Fourier - Transform Infrared Spectrometry by Griffiths and Haseth. I believe I understand the theoretical principles...

The energy emitted by a body in watts/m2 is = εσT4. In the case of a perfect black body, ε=1. If the body only emits IR light, what should be the value of ε?

Hello, I'm looking for a gas (hopefully one that is readily available) that will absorb Nd:YAG laser radiation at 1064 nm. The purpose is to heat the gas to transmit heat into a glass fiber composite which normally does not absorb IR light.

Microwave oven operates at 2.4 GHz. Consider the situation of making tea or coffee in Microwave where water is heated to 100C to boil. Looking at Planck's law / Wien's law, 100C (373K) corresponds to a peak wavelength of 7.8nm or 38.6THz which is in Mid Infrared. Effectively materials...

Homework Statement The infrared spectrum of CO shows a vibrational absorption peak at 2170 cm-1 (a) What is the force constant of the CO bond? (b) At what wavenumber would the corresponding peak for 14CO occur? Homework Equations k=ω2μ = (2πcv)2μThe Attempt at a Solution So I solved part a...

I've read that H2O has an absorption/emission band around to 10 micron range. What conditions are required for photons of this wavelength to be emitted by H20 gas? In particular, how hot would the gas have to be? What amount of pressure is required? Under everyday conditions (like steam possible...

This is about a debate (argument??) I am having on another forum in which people are claiming heat can be transferred from greenhouse gases in a cooler atmosphere to a warmer surface (that allegedly warmed it). The so called back-radiation is presented as a positive feedback which warms the...

Hello, Every member: We need to IR sensor solution for our system. Please, connect to me If you know any company of product or maker about the IR sensor. Required specifications are as follows: (ps: choose one of the following five.) 1. Thermopile array #1: a. Pixel pitch: 0.6 mm b. Array...

Dear Everyone, I'm searching for some specific elements for infrared (IR) sensor, such as Thermopile, Pyroelectric, Bolometer, MCT(HgCdTe), PbSe, or InSb sensors. Does anyone know how to get these kinds of elements ? ( I need some information about the manufacturers...) The elements are...

The question is in the title: is it possible for a theory to be both UV and IR stable? And concrete models would be much appreciated!

Hi! I would like to ask some general question about IR spectroscopy. During absorption of IR photons two quantities have to be conserved, energy ##\hbar \omega_{photon} = \hbar \omega_{phonon}## and momentum ##\hbar k_{photon} = \hbar k_{phonon}##. Wouldn't these two quantities be conserved at...

Hi! I'm trying to design a device to detect eye blinking while a person is sleeping. I have tried to use TCRT5000 sensor (http://www.vishay.com/docs/83760/tcrt5000.pdf) in the prototype and it works like charm ! However, since the TCRT5000 sensor has an IR emmitter I have some safety...

Hi! I'm part of a team doing an engineering project to design a device to detect eye blinking while a patient in the hospital is sleeping. We have tried to use TCRT5000 sensor (http://www.vishay.com/docs/83760/tcrt5000.pdf) in the prototype and it works like charm ! However, since the...

Hi I was wondering if anyone could tell me what gasses are absorbed between 800 and 1000nm wavelength and weather there is a book that lists all the gas wavelengths that can be absorbed in this region Thanks bertopolis

Hi I was wondering if someone could tell me what kind of gases I could expect to see using an IR receiver between the wavelengths of 110 and 330 nm. As well as this id love to know what kind of glass could be used in order to not interfere with the actual results. Thanks a million

Hi all, I want to get some sort of polymer that is opaque to infrared (absorbs wavelengths above 700 nm very well) but transparent to visible light (does not absorb much light below 700 nm). Does this even exist without being a meta material?

Homework Statement I am trying to help my daughter determine the structure of this carbon compound. It has seven carbons, 14 hydrogens and one oxygen. The oxygen must be in a ketone group. Also each carbon is different (as indicated by the carbon 13 NMR). Homework Equations The Attempt...

Hi evryone. My name is Lucian, I'm a Computer Engineer. I'm working in a project of a company to develop a flow meter using a microcontroller and Infrared sensors. I'm stuck in the mechanic fluid part. We're trying to develop this product basing in the mechanic model of the attached picture...

1. Homework Statement Hi, I have to do lab experiment - estimating infrared wavelength (from remote control). My experimental setup includes CD, remote control, webcam (without IR filter, so I can see the infrared radiation), sheet of paper (I will see diffracted light spots on it) with hole...

I understand that asymptotically free theories must be based on UV fixed points rather than IR ones, because the RG flow goes into rather than out of an IR fixed point, so an asymptotically free theory based on an IR fixed point is trivial at low energies. But at higher energies the coupling...

Hello Forum, Why are infrared (thermal) cameras, those that produce interesting thermographs of objects, mapping their surface temperature, so expensive? IR sensors are ubiquitous and very inexpensive...What is the difference? thanks, fog37

Homework Statement Why is the formula for internal resistance for a charging battery v = e + Ir? When the battery is supplying I to the circuit I understand why the terminal voltage, V, equals emf - IR (voltage lost by internal resistance), but if a battery is charging, why is the...

Well! the material to be freeze-dried is irradiated with IR radiations before, why?? Also I am confused as to how can ice sublime at atmospheric pressure?? Isn't the triple point of water much lower? is the vacuum around the material created for this reason? ( to lower the pressure I mean) Also...

I have been struggling with the following; (apologies if this is a simple question) After reading the Hershel experiment where with a prism light was used to split white light into a spectrum of colours and the red light was warmer than the violet light, then he placed a detector past the red...

Hi! a very basic question that probably has a simple answer: would it be possible to trace a laser moving over a generic surface such as a wooden floor with an IR camera? The idea would be to calculate relative movement based on that... If I'm not clear enough feel free to follow up with a...

Hello, I am new here so my apologies if I have posted in the wrong place. I am trying to amplify the radio waved I get from a receiver to power led that will ultimately be used as a remote for the AC. I have contemplated "charging" a capacitor until it has enough power to power the led...

Can anyone speak on the spectrum of sunlight reaching the upper atmosphere and the surface ? Specifically I interested in finding out if there are any IR wavelengths disproportionally represented when compared to the original source. Please limit responses to constructive ones.

If you had a voltage v and wanted to know current, would the current be infinity ? Do we just call it 0 because it is insignifant to find such a useless number because since there is no resistance it would be too high. I figure if r=0 then I = v/0 so infinity?

Hello all, I am looking for easy to obtain materials, preferably in powder form, with good absorbance at 808nm, 365 nm and 404 nm each (either one material for each wavelength or one for all three).However I can't seem to find absorbance charts. Does anyone have any idea either on which...

I received a handout at university that I believe could be erroneous. It states. "IR radiation has a higher potential to warm objects than UV light. Does IR therefore have a higher energy level?" It refers to E = hf Note it mentions 'UV light' but 'IR radiation', not written by a...

Hi everyone, I have a problem a bit tricky to solve which deals with Infrared absorbers. In my setup experiment, some IR radiations are emitted, let's say black body radiations at 300K, so IR wavelengths centered on 10,6µm. I want to absorb them (entirely) by a surface (at about 77K) made...

When analyzing the absorption pattern for different compounds when radiated by IR radiation, we see the wavelengths of the IR lights that is absorbed. These wavelengths correspond to the frequency at which the bonds in the molecule vibrate. My question is why a compound, for example an alcohol...

Modern cell phones seems to come with IR filters on their cameras. I want to do an experiment to figure out what wavelengths these filters allow to pass and which they block. How would I go about doing this? Also, what sort of equipment would I need? I am a university student so I have access...

Hi, if I have a DC indoctor-resistor circuit with and inductance (L) of 700μH and a resistance (R) of 0.8Ω, I realize that I can use: IL = (Vsource/R) * (1-e-t*(R/L)) to calculate the current through the inductor if I have a constant voltage source, but would it be possible to calculate...

I am working on my thesis for my masters in physics, and am running into some issues while trying to gather an IR spectrum of my hydrogenated amorphous silicon (a-Si:H). I am depositing my films using PECVD onto a glass microscope slide substrate. The films I have used so far have been 0.2-0.4...

At a particular wavelength (In IR range), & at particular temperature, can anybody or coating has different IR emissivity & IR absorptivity?

I have a part with a 2.5mm hole that sits inside a fixture (I need to verify hole presence), the hole can move anywhere around the slotted area due to part flexing, install force, etc. One idea I had was point an 850nm InfraRed light from the other side at the hole, then mount an IR light...

Here is the question: Here is a link to the question: The equation z3 + az2 + bz + c = 0, where a, b, c are real, have a purely imaginary root (i.e. the real part o? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.

My general question is: can high energy photons convert into many lower energy photons? Could the reverse reaction occur spontaneously? Let's say we have a single photon that was emitted from a distant supernova. We detect it here on Earth. The photon hasn't converted into multiple lower...

This feels silly asking but I have a question about units using the double harmonic approximation to determine IR spectral intensities. In the double harmonic approximation the intensity is given by the square of the derivative of the dipole with respect to a normal mode coordinate times a...

Hi, I currently have a black body calibration source which I use for work. It works great, I can calibrate all the IR thermometers just fine, however it isn't a simple quick "check". The IR thermometers are the ratio type in that they measure two wavelengths and using the ratio it can work out...

Hi all, I am looking for the best material for IR (infra red) absorption, preferably something that I can make it into a thin film; any material that would work from semiconductors, metals to more exotic materials like graphene or... I appreciate your help. Thank you

I am considering purchasing an in-car camera such as this: http://www.ebay.com/itm/Vehicle-Car-DVR-Recorder-Camera-Road-Safety-Guard-6-LED-270-2-5-TFT-LCD-Screen-/281082214101?pt=US_Surveillance_Digital_Video_Recorders_Cards&hash=item4171ce36d5 The device has six infrared lamps to...

A physics stack question asks why when the air is hotter then your body thermodynamics allows your body to operate as a heat engine as a heat engine must have a sink for waste heat. See question here, http://physics.stackexchange.com/questions/59316/human-as-a-heat-engine Part of the answer is...

I am currently in training to become an analyst using thermal imagery. In the studies I have been introduced to cold sky reflection on thermal imagery, however the instructor explained it as a surface 'reflecting the cold from the sky' which, as far as I'm aware, doesn't fit with the second law...

Hi There Am training to be science teacher at secondary school. A few issues have arisen for me lately and would like clarification: Issue 1: have been studying electromagnetic spectrum with my year 10 class. We have discussed Herschel's experiment in which he discovered IR radiation by...

Homework Statement The question states to identify which graph is associated with which molecule, which are CF4 and CF2Cl2. The graphs are measurements of infrared spectra, one has one peak while the other has two. It then asks to determine which symmetry labels are associated with each peak...

Is it possible to bombard Ir 193 with alpha particles to create Au 197? If it isn't why not? And if it is why has no one done it yet?

CO2 is supposed to create a "doublet" peak at 2350 cm-1 according to my IR correlation chart. Why is this doublet created? As DrDu explained in my previous post, two peaks are seen for the N-O bond because it has IR-active symmetric and asymmetric stretches. But CO2 is a linear molecule, and...