What is Shielding: Definition and 155 Discussions

In electrical engineering, electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. Shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. Electromagnetic shielding that blocks radio frequency (RF) electromagnetic radiation is also known as RF shielding.
The shielding can reduce the coupling of radio waves, electromagnetic fields, and electrostatic fields. A conductive enclosure used to block electrostatic fields is also known as a Faraday cage. The amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of holes in a shield to an incident electromagnetic field.

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  1. Bhumanyu Arun

    Can the potential inside a metallic cavity electrocute someone?

    My question was was that though you don't have any charge on the inner surface of a metallic cavity but still there's a potential. Can't that potential electrocute someone?
  2. G

    Question for grounding of the electronics to Faraday cage

    Hello. Let's say there is a instrument needed to be EM wave-shielded in High voltage discharge lab. Building Faraday cage becomes necessary and the instrument is moved to inside the cage. The cage is grounded to lab ground and the frame ground of the instrument (it is also signal ground for the...
  3. akashverma

    Thickness of steel required for shielding magnetic field

    thickness of steel plate required to stop interaction between 3' dia neodymium magnet
  4. E

    High Frequency Servo shielding and grounding on robot?

    I have an issue that appears to be relating to noise mitigation and grounding. Some background on myself is I have a mechanical engineering technology degree. But my job requires an ability to work with and troubleshoot electrical issues. Currently a customer is using a Servo motor on an end...
  5. T

    A conductor shields its inside from its outside but not vice-versa

    A point charge outside a hollow conducting sphere will produce no field in the hollow interior: the metal shields the interior. But a point charge inside the hollow interior will produce a field outside: the same metal ceases to act as a shield. Why is this? (In particular, aren’t “inside” and...
  6. Krack

    Shielding & ground loop for audio

    I have a 3 conductor wire that are all wrapped in a foil shield with wire conductor, for a total of 4 wires. I am connecting the 3 inside wires to audio left, right, and ground. This is an unbalanced setup, right? Where/how do I connect the shielding? Do I connect both sides (i think no)...
  7. I

    EMF radiation shielding and dirty electricity

    Hello, Does anyone shield themselves from computer / monitor from EMF radiation? if so what materials do you use to cover/coat your electronics? I am buying an EMF meter soon (Trifield 100XE) and plan on solving all my EMF issues, specifically around my computer tower, monitor, and other...
  8. S

    Shielding simulation and nuclide vector

    I have to make a shielding calculation of some radioactive scrap metal in a cask, using Geant4 (hence Monte-Carlo). I will be given a nuclide vector and I'll have to calculate the ambient dose equivalent rate outside of the cask. The nuclide vector I will be given will be something like: Co60...
  9. H

    Optimizing Orbital Shielding: Comparing 1s, 3s, 4d, and 5s Orbitals

    Assuming all orbitals are filled, which of these orbitals is most shielded: 1s, 3s, 4d, 5s The answer is 4d, but I chose 5s. Can someone explain? I thought the electrons in the d block are considered core electrons and contribute to the shielding, but feel more pull from the nucleus because of...
  10. M

    Magnetic Shielding for Motion-Based Project

    Hi, I'm working on a project, interested in your opinion Need a material for magnetic "shielding" There must be no repulsion or attraction between M1 and S since non of them is stationary and it would affect the motion. There will be a ferromagnetic material behind S that cannot be affected...
  11. D

    Can we explain shielding effect using electric field ?

    i want to specifically focus on the mechanism inside an atom . suppose there are some electrons in the nth shell of the atom. They reduce the effective nuclear attraction on the electrons in the (n+1)th shell. can we say that the vector fields of the n shell electrons and the nucleus superimpose...
  12. @

    Electrostatic shielding in a cavity

    Suppose a constant electric field exists in space as shown in the file and a open lid cube type conductor is brought inside the field. What would be the electric field in the question marked area. Would it be zero or equal to original electric field.
  13. Qw_freak

    Calculation of gamma ray shielding value in liquids?

    Hi folks Please bear with me, I'm new here and this may not be the correct forum to ask this question. If this is the case, I'll of course remove my question and ask it the appropriate place instead. However, here it goes: I need to be able to calculate how much a given intensity of gamma...
  14. .Scott

    How Do You Shield a Compact Fusion Reactor?

    After Lockheed Martins announcement that they were developing a fusion reactor that might fit on the back of a pickup truck, I got into a conversation with someone about how one would shield such a device. So I found some tables that described the cross section of protons at different energy...
  15. A

    Electrostatic shielding and capacitors

    First before asking the original question i need to make sure some of my concepts are correct: 1- what happens when a capacitor with its 2 plates having different areas is charged? according to this forum https://van.physics.illinois.edu/qa/listing.php?id=23409 as the long as the difference in...
  16. K

    Electrons in s-robital shielding outer electrons

    Why do electrons present in spherical shaped s-orbital shield the outer electrons from the nucleus more effectively as compared to electrons present in p and subsequent orbitals? Please explain in a layman language I'm just in class 11th. :/
  17. A

    How does radiation shielding using absorbing materials work?

    I understand that, for example, a thick enough sheet of lead can absorb gamma radiation, but I want to understand what actually happens at the molecular/atomic/subatomic level. Also, can the same logic be applied to cosmic particles? I have tried Googling for an answer, but to no avail. Can...
  18. M

    X-Ray Shielding: Importance in Medical Technology

    Why x-ray shieldings are important part of medical technology?
  19. M

    Why lead is used for radiation shielding?

    I heard that many industries use lead for shielding harmful radiation. do you know why?
  20. D

    Shielding - Need to ground an electrostatic shield?

    Shielding -- Need to ground an electrostatic shield? I am reading this app note by analog devices: http://www.analog.com/static/imported-files/application_notes/41727248AN_347.pdf At the bottom of the first page it says: "An electrostatic shield, to be effective..." "But grounding the...
  21. A

    Question about magnetic shielding

    so i understand that if there's a piece of metal between 2 repulsing magnets, the magnets attract to the metal as well, and the repulsion could cancel out the attraction... right? i mean is this even true. if not why not... if it is true, then is it possible to have 2 wheels of repulsing...
  22. soothsayer

    Can lead shielding block beta particles?

    I know lead is a great shield against gamma particles due to its extraordinary density, but I wonder if it can also block beta particles, or is it transparent to them due to being electrically conductive? Thanks ahead of time for your responses!
  23. S

    Some questions about neutron shielding in fast reactors

    I've been reading about fast reactor designs lately (not necessarily ones that have actually been built). A few articles I've come across < https://drive.google.com/folderview?id=0B-MNeRy61MgpTVExcUQ3T3ZWWG8&usp=sharing > discuss the possibility of building fast reactors, fueled with molten U...
  24. I

    Meta Materials as Cosmic Ray Shielding for Spacecraft?

    While thinking about the recent-ish developments in meta materials for 'cloaking' systems, a thought struck me: could a meta material or combination of meta materials (probably of a somewhat more advanced state than they currently are) be used as a form of shielding from cosmic rays of various...
  25. G

    Effect of Shielding on Electron Penetration

    as i have understood, in a many electron atom the degeneracy is lost due to shielding effect. and from quantum mechanical model of one electron atom we can say that keeping principal quantum number(n) fixed, the radius at which radial probability function takes maximum value decreases with...
  26. M

    Energy Self-Shielding: Explaining the Concept

    Can someone explain the concept to me? As far as I know, in some energy interval there are materials which have resonance absorption. The book then goes on to say that energy self shielding does something to combat this absorption but I am not clear on how and hope someone can clear this up for me.
  27. M

    Shielding Wire: Reduce Field at Point 30mm Away

    Hi, how can we reduce field at a point(of observation) 30mm from a 10 m long blank copper wire with return path somewhere at infinity carrying DC current by using a 1m long copper tube 1mm wall thickness and 30mm outer diameter?
  28. C

    Magnetic Shielding of Detectors

    My professor has given me a project, figure out how to magnetically shield some detectors which surround a solenoid. Now, we have mumetal tubs which fit the detectors, but he wants numbers. The solenoid outputs a maximum of 6 Tesla, and it's in a dewer, so there's no way for me to perform actual...
  29. B

    Shielding a single AC current carrying wire.

    I was thinking whether it was possible to shield a portion of a circuit that has only a single conductor without a return path. The frequency is high enough for the Earth's capacitive impedance to be low. Is my assumption then correct that the induced voltage in the shield will create a...
  30. D

    Shielding calculation with MCNP5

    Greetings to all I had some problems using MCNP5 for gamma shielding calculation. The original input file is from a document by George E. Chabot, Jr., PhD, CHP Shielding of Gamma Radiation. The description of the problems are following: 1) Three different shielding materials, namely...
  31. A

    Essay on what materials are best at shielding electromagnetic pulses

    So I am in the IB, and I have to do an extended essay. I'm doing it in physics, and I'm looking at the topic "What materials offer the best shielding against an electromagnetic pulse (EMP)?" I was thinking of measuring the electromagnetic pulse using an oscilloscope. The reason I want to...
  32. B

    Clarification of forces involved in electron shielding

    In my chemistry class we just started doing stuff with ionization energy, atomic radius, etc., and I've heard the phrase "electron shielding" tossed around a lot. When I tried to look it up online, most places use "shield" as the verb describing this process, which is not very helpful. The most...
  33. S

    Magnetic Shielding Strategies for Reducing Attraction Between Two Magnets

    First I am sorry if this question is not quite related to this forum. But I have not where to go So I just post it here hopfully one can help. Thanks in advance. I have two strong magnets. Each has around BrMax: 13200 gauss and pull force 27 lbs. I am looking for a magnetic shield...
  34. S

    Robot Project: Shielding Electronics in HV Environment

    Hi, I am doing an university project that consists in building a robot that operates in a AC to DC convertor. The robot has to work under HV environment. I am looking at possibilities of shielding the electronics of this robot. Can you give me any suggestions or links to look at? Also, will...
  35. A

    Is Guitar Shielding Just a Myth?

    Ok, is doubt this actually works well. Some guitarists shield their guitars in the cavity of the pickup and the pick guard with conductive foil. This is supposed to work like a faraday cage. The pickup is basically a solenoid that "pick ups" the magnetic field from the magnetized string. So...
  36. S

    What Makes Aluminium an Effective Thermal Radiation Shield?

    Hi all I'm doing a project for energy efficient buildings with thermal insulation.(Just a leisure project and I am not technically that strong!) This is about thermal radiation shielding. My understanding is that Aluminium has higher reflectivity (Hence lower emissivity ) so that it...
  37. P

    Shielding Magnetic Fields: How Can We Measure and Contain Them?

    Hi everyone, I have two questions related to magnetic fields. Firstly, if I have two bar magnets with opposite poles facing each other, ie NS - NS, how do I measure the magnetic field strength at any point between the two magnets? Secondly, how would I shield the magnetic fields of the...
  38. C

    What is the Impact of Sheetmetal on Electromagnetic Signal Propagation?

    Hi I'm wondering what properties affect the propagation of electromagnetic signals. I am interested why an aluminium case would adversely affect signal propagation, for example in this case, here And why is it that a small gap in that casing will allow signals to propagate? (is the...
  39. R

    Emi/rfi blocking problem, shielding

    my scenario: so we are working on a problem in a building and are struggling with making the top floor (cable and other assorted digital equipment) playing nice with the bottom floor warehouse (digital ballasts on the ceiling). my question: where does the interference 'come from'? light...
  40. I

    Designing Shielding Box for High Voltage Cylinder

    i have to design one shielding box. in that there is cylinder having high voltage +60kev. and box having metal plate. so i have to calculate the electric field on that cylinder and then decide , what should be the distance in between plate and cylinder. i have attach the geometry on the file...
  41. S

    Why do I get a higher radiation intensity with slight shielding than with none?

    Homework Statement I did a radiation lab a few weeks back. The task was basically to map out radiation intensity as a function of shielding thickness. A Cs137 gamma ray source was used, and lead was used as the shielding material. Data was taken meticulously and over long periods of time so as...
  42. A

    Would a relativistic ship really need much shielding?

    Hi all, It doesn't seem that a relativistic ship traveling in deep space would need much shielding due to particles at rest in the space frame, appearing relativisitc now in the ship's frame. Here's the calculation I did: Let's imagine a ship the size of a space shuttle traveling with γ of...
  43. R

    High Voltage Shielding: Choosing the Right Coaxial Cable for 6 kV Applications

    hello. I need to use a "coaxial" câble with 6 kV on axial wire. May I use a TV coaxial wire ? Will it be able to support such voltage. Anyway I must transport this HV and it must be shielded. A suggestion ?
  44. L

    Shielding for common mode currents

    Let's say a shielded cable is in the vicinity of noisy environment with plenty of EMI. How to go about cancelling the common mode currents, so that the magnetic field gets cancelled. It's pretty simple in case of differential mode currents. The mag field from the forward current and return...
  45. B

    Can Water Flow Between Plates Shield Radiation Without Pressure Build-Up?

    I just read a short story about a post apocalyptic world in which humanity was on the brink of destruction due to the loss of protection from the planetary magnetic field (pole reversal in progress, process turns out to take some 100 years to finish). Electronics go haywire and large amounts of...
  46. S

    Magnetism: conditions for magnetic attraction and magnetic shielding

    Hi, I have two questions that come from a unique example of magnetism. Here is the scenario: a thin and long piece of iron is placed in between a magnet and the north pole faces the outing sheet and some iron tacks. The iron tack do not get attracted to the iron even though a south pole is...
  47. N

    Californium(Cf)-252 shielding design

    Hello , If I wanted to design a radiation shield to protect from line source of Ca-252 with 5.3 Ci what is the first thing I should think about..?
  48. C

    Circuit and Shielding Problems

    Two tricky MC problems from Halliday/Resnick: 1. A point charge is placed inside an uncharged spherical conducting shell, somewhat off center. However, the charge distribution on the outer surface of the shell is uniform. Why? 2. What is the minimum number of resistors necessary to make a...
  49. A

    Magnetic Shielding for Motor Control Center

    Hey guys and gals, I'm not an electrical-anything so please forgive my lay-person speak. I work in a lab. One of our rooms has a high magnetic field. It is causing interference with some analytical and computer equipment. Of course there is some health concern as well... Half of this...
  50. B

    View-factor and emitter shielding

    Ive been having discussions with a colleague of mine about the most accurate method of calculating a view-factor when there is an object between the receiver and emitter. I was hoping someone could provide some advice on the matter. Basically I am trying to model the radiant heat flux of a...
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