This is consistent with what I found.īy contrast, when measuring the Pi's WiFi antenna (while doing a ping -f -I wlan0), it was difficult to detect any decay at all. Presumably a well-designed single-board computer would try to avoid large high-frequency current loops, even if only to save power, and so its assorted clock radiations would have similar decay properties to an Ethernet cable. That law is for monopoles, where for example an Ethernet cable would have many small loops of opposite orientation which cancel out at larger distances, thus decaying faster than 1/r^2. My conclusion from measuring these things, and thinking about the physics, is that the field is decreasing much faster than the "inverse square law" we learn about in school. With the meter held against the Pi case I got a much higher reading, 10 mW/m^2. For comparison, an Ethernet cable was only detectable at 2 inches. I could detect RF radiation from a Raspberry Pi 3B+ about 3 inches from the plastic case, beyond that it was indistinguishable from background. Near the floor of my ground-floor room, the RF background reads 0.02 mW/m^2. I purchased a "TriField" EMF Meter Model TF2 out of general curiosity. If you Google diy rf meter you'll find a number of devices that you can build or buy that will give you insights into emission levels (and therefore potential issues). For example, if we were having a conversation, and you had asked me this question, my reply would have been something along the lines of, "I believe RF Emissions from the RPi are quite low based on the fact that they have demonstrated compliance in the EU and USA." Anecdotally, I've yet to see or hear of an emissions issue in an RPI project that wasn't caused by "improper" wiring or interconnections.įinally, there are some tests that can be done (relatively) inexpensively in limited portions of the spectrum. ![]() Still another way to answer your question is through opinion and anecdotal evidence. You may wish to peruse the documents applicable for your country. It provides compliance documents (which include emission levels) for all products in all countries for which certificates have been assigned. ![]() Perhaps one way to answer your question is to point you to the Raspberry Pi's Product Compliance matrix. ![]() And if you did have the specific answers, they will only have meaning if you were familiar with the testing standards, or knew the susceptibility of all the items in your environment. "How much it is radiating in the RF spectrum?" is a question that's easy to ask, but not to answer - at least not specifically.
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