One of my old professors developed radiation-hardened orbital sensors for NASA. From what I remember of his lectures, I think a refrigerator is probably a terr

One of my old professors developed radiation-hardened orbital sensors for NASA. From what I remember of his lectures, I think a refrigerator is probably a terrible Faraday cage. Here are some excerpts from a nifty Analog Devices tutorial about RF shielding[1]. This is probably the most relevant part: The longest dimension (not the total area) of an opening is used to evaluate the ability of external fields to enter the enclosure, because the openings behave as slot antennas. Remember those big rubber seals on the doors of most refrigerators? It then goes on to describe an equation for approximating the shielding effectiveness at a given frequency: Let λ = wavelength of the interference Let L = maximum dimension of the opening Shielding Effectiveness (dB) = 20 * log10(λ/2L) And here's a nice rule of thumb: A rule-of-thumb is to keep the longest dimension less than 1/20 wavelength of the interference signal, as this provides 20 dB shielding effectiveness. There's other stuff in there, such as how to properly shield cables entering or exiting the box. (Unshielded wires penetrating the box can also act as antennas.) Worth a read, if you're curious. [1] "EMI, RFI, and Shielding Concepts", Analog Devices, http://www.analog.com/static/imported-files/tutorials/MT-095.pdf http://www.analog.com/static/imported-files/tutorials/MT-095..., Page 10