Why do Faraday bags for phones need an insulation layer, while Faraday cages in science museums with people inside don’t?
I understand the metal layer is required so EM charges have a conductive route to pass through without entering the Faraday cage/bag. I understand that Faraday bags have an insulation layer under the metal layer, that is placed between the metal layer and the protected object, so that EM charges are blocked and don’t pass through whatever’s in the Faraday bag.
What I don’t understand is why this layer is not required in Faraday cages in science museums, where a volunteer is placed inside the cage and then the cage is lit up with high voltage electricity around, arcing through the air. What’s there stopping the electricity, which is already arcing through the air due to the high voltage, from arcing into the Faraday cage and reaching whatever’s being protected?
Please let me know if more information is required.
In: 2
Faraday cages are big metal structures. They can be built to sustain their own weight.
Little tiny strands of metal are very flimsy. If there was no insulation layer on the bag, the metal would buckle under any force.
Geometry is also very important for faraday cages. The spacing between the wires determines what frequencies of EMI are attenuated and reflected. If it was just metal, you could change that structure and ruin it’s properties. The plastic gives that structure the rigidity and flexibility required to handle everyday use.
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