I'm supposed to measure temperature with an infrared camera. But when used on materials such as gold and aluminum or iron I get false readings (the emissivity is low). To solve this problem I figured I would need a paint that gives the surface high emissivity (low-reflective).
My question...
Homework Statement
This isn't so much of a homework but rather I am trying to understand the physics. The solution to the radiative transfer for a isothermal homogeneous gas of layer consists of one part that describes the absorption and one part that describes the emission.
My...
Homework Statement
Hello, I'm a little confused. I did an experiment today with a Leslie Cube. One of the faces was a black paint, and another a white paint. I know that white reflects well and has a low emissivity, at least in the visual wavelengths. In the Leslie's cube, was hot water, so...
Homework Statement
A tungsten filament in a lamp is heated to a temperature of 2.30 x 10^3 K by an electric current. The tungsten has an emissivity of 0.31. What is the surface area of the filament if the lamp delivers 35.0 W of power?
Homework Equations Stefan's Law
(a greek letter...
Hi first time posting so apologies if this is the wrong section to post this in!
I'm having a bit of trouble defining the difference between reflection and emission on the atomic level. As far as I can see both just essentially involve excitation of an electron by a photon, followed by...
I'm having problems measuring the temperature of a steel surface with varying emissivity with a pyrometer. So I thought one way to overcome the varying emissivity is to paint the surface with a paint that has a high uniform emissivity in the IR region.
The paint should:
Have high...
Homework Statement
I am given a plasma at 8000 Kelvin and assume its an ideal blackbody. I have slit of 0.01 cm^2, observing at wavelength 325 nm with a spectral bandwidth of 0.05 nm.
The problem asks that the actually continuum under these conditions is 1 pW. What is the emissivity...
Hi,
Can anyone give me any information on where i could find information on the emissivity of a gas, particulally argon, or how i can calculate it? i am trying to create a graph of heat transfer against temperature and see which plays a larger role at particular temperatures when transfering...
Hello,
I have a Tungsten filament radiance source that has been calibrated in the UV region and would like to extrapolate the radiance to longer wavelengths. By calibrated, I mean, a NIST plot of spectral radiance v. wavelength at a certain set of operating conditions.
I'm new to this...
Hi, I am stuck on this question, any help would be appreciated. Thanks!
The tungsten filament of a certain 100 W light bulb radiates 2.85 W of light. (The other 97.15 is carried away by convection and conduction) The filament has surface area of 0.400 mm^2 and an emissivity of 0.952. Find...
If the emissivity of a flat surface varies with zenith angle according to
e=E*cos(theta)
where E is the emissivity at zenith.
Would this surface radiate isotropically?
I think that because the emissivity varies then the emitted radiation varies accordingly so the energy measured from...
If the emissivity e varies with zenith angle according to e = E*cos(theta) where E is the emissivity normal to the surface. Would this surface be an isotropic source of radiation?
Well, since e varies with angle then the flux density must vary accordingly so the surface would radiate...