SmartThings Community

RF radiation level concerns


#16

I haven’t thought about the bulbs until i read your post. What i can tell you is that all battery operated Zigbee sensors i have measured with an EMF meter ( a semi pro one that i have rented) seem to be actively transmitting for a fraction of the time. I do not know the exact duty cycle but i guess it should be less than 10 per cent of the time. Probably even less than that.

Problem is, when i had the EMF meter i did not even think about measuring the bulbs… Yeap.


#17

Yeah, the battery-operated devices have very low TX output and they only transmit when needed. For the Hue bulbs, things are different. They transmit a lot (as in a burst every few milliseconds, and they’re constantly polled by the hub). It all boils down to the actual transmit power used - not sure it’s a good thing that Philips won’t publish that data.


#18

I tried again and today I actually received an answer to my question from Philips. I’m not sure if I’m supposed to publish exact values here as it was part of a closed conversation - but I think it’s ok to say that the transmitting power is at the very low end of the Zigbee standard (nowhere near the 100mw that they could use if they wanted to) and corresponds with battery powered devices. My worries were unfounded - the levels are about the same as for other low-power devices (such as Z-Wave). I’m guessing a standard socket emits about the same electrical field.


(Aaron) #19

I’m an Amateur Radio operator licensed up to 1500 watts… it is all over for me.


#20

Thanks for the info.


#21

Dude, do you really have smth that emits 1500W somewhere near you?

Seriously?


(Aaron) #22

I said I was licensed up to 1500 watts… I don’t sit next to an antenna transmitting that kind of power.

I current only have a 50 watt VHF/UHF transceiver in my Jeep. I have operated a 1500 watt VHF transceiver before with the antenna only 1 floor above me. We always locked down the roof when transmitting.

I also have 100 watt HF transceivers but I do not have them setup at the moment because I moved last year.

Guess my point is, 100mw is nothing.


#23

Power is only one thing to consider. Wavelength is also important. Still 1500 watt is too much and yes 100 mW sounds like a joke next to what you are talking about.


(Aaron) #24

Think about the people that live next door to a 10,000 watt FM-radio broadcast antenna. Some of the radio stations in my town have open fields with transmitters right in the middle of neighborhoods.

Example 1: https://www.google.com/maps/place/Kail/@36.8436543,-119.6879858,473m/data=!3m1!1e3!4m2!3m1!1s0x0000000000000000:0x9ef8d7bedc91fd03

Example 2: https://www.google.com/maps/place/Radio+Guadalupe+Mission+Inc/@36.7694505,-119.7517876,475m/data=!3m1!1e3!4m2!3m1!1s0x0000000000000000:0x25d3624d646bea7f


#25

Signal power drops very much with the distance. It all has two with how much power is emitted, the frequency, the distance from the source and time.

Still, with a 10kW transmitter you need a good a distance in order for the signal to drop significantly.

I do not know if such an FM transmitter in the neighborhood causes more damage than talking on he cellphone for 6 hours a day at a place with pretty bad reception.

One has to check for himself with an EMF meter.


#26

I got an EM meter today after the results of that state-funded cancer study were pretty concerning. Checked out the house and I’m not worried. The EM radiation from the WiFi access point drops to unmeasurable in about 3-4 meters distance. The Hue base station emits considerably less radiation than the AP. The bulbs emit about 1/3 of what the base station does. The frequency of the transmissions seems to have to do with the individual bulb’s position within the mesh network. One of the bulbs seems to be a central node and that one transmits pretty much permanently, albeit at a low transmit power. The EM meter only picks it up to about 50cm distance. The other bulbs transmit short bursts every 3-4 seconds, so overall, that’s perhaps about 15 seconds per minute. So they’re idle for 3/4 of the time. The Hue White and Ambiance bulbs seem to be transmitting less than the color version.

The main factor for radiation at our home is the mobile phones. Even if only WiFi is on, they seem to emit the same amount of radiation as the access point (almost 100mw) and we pretty much constantly hold them in our hands.

Oh, and the ZWave bulbs transmit drastically less and at much lower TX power than the Hue bulbs.

The EM meter only covers the 800 - 2500 MHz band, so I can’t sad how other things (like LED bulbs etc.) behave. It’s also not the most expensive model, but it’s relatively accurate I believe.


LAN over microUSB for Netatmo devices?
#27

Thanks for your feedback. Which EMF meter did you use?


#28

hi,

I’ve bought this one: Gigahertz HF32D HF-ANALYSER (available from Amazon and other online shops). Not necessarily cheap, but I reckon it’ll be useful in the future as well. Already helped my parents re-arrange their WiFi AP and change some stuff at home as well, to make sure the bedrooms get as little EM exposure as possible


(Steve White) #29

As a ham radio operator for 24 years and broadcast engineer for 19, I find this pseudo-science focusing on almost immeasurable exposure to RF radiation rather amusing. Science could not provide proof that RF from a cell phone was harmful despite dozens of studies and millions of dollars spent.

The bottom line is that those of you who are concerned about the tiny amounts of RF being generated by Zibgee devices had better not fly or have an x-ray taken, or even spend a day at the beach. You’ll receive far more harmful exposure doing any of those activities.

And for the record, I occasionally work in a transmitter building just a few hundred feet below a UHF antenna operating a 1.1 MW ERP. Yes that is not a typo, the antenna gain calculates out to a 1.1 megawatt effective radiated power.


#30

Hi there,

I am not sure i agree with you. BTW, there has been at least one scientific paper that got some publicity in the last few days that correlates cellphone radiation to cancer.

I totally understand your point if indeed the RF amounts of Zigbee are tiny. But are they? Who decides what is tiny? By the way, if i was smoking two packs of cigarettes a day i would never worry about the radiation staff. But having a small baby makes you rather more concerned about “the little things”, if you know what i mean.

Also, people in Europe are generally more sensitive to radiation issues than they are in the States. This is a personal observation but not far from the truth i think.

Thanks for your input.


(Ben W) #31

Most scientific studies are never peered reviewed and make loose correlations.

John Oliver explains it well


(Steve White) #32

Anyone can make an argument that something is harmful. Indeed, just about anything in excessive quantities is harmful, even fatal. You can breathe too much oxygen, drink too much water, or consume too much sugar. We know that too much sun exposure causes cancer, but you can also fall ill and from living in darkness. Cigarette smoke is clearly bad, but so is smoke from a campfire. Even cooking food, which humans have done since the stone age, has been linked in some studies to cause cancer. Where does it end?

Point being, everything, at some level or quantity is bad for you. At higher frequencies and power levels, RF exposure is no laughing matter. You wouldn’t stick your hand in a microwave oven would you? However the reality is, the levels we are exposed to every day by WiFi routers, cell phones, etc. has never been proven harmful by any peer-reviewed and peer-accepted study. That’s a fact.


(Dave Davis) #33

Point being, everything, at some level or quantity is bad for you. At higher frequencies and power levels, RF exposure is no laughing matter. You wouldn’t stick your hand in a microwave oven would you? However the reality is, the levels we are exposed to every day by WiFi routers, cell phones, etc. has never been proven harmful by any peer-reviewed and peer-accepted study. That’s a fact.

What?

http://www.powerwatch.org.uk/science/studies.asp


(Donald Kirker) #34

I am not going to offer any argument or opinion on whether I think those papers that are published are real or just fear monger, mainly because I have no background as a scientist in the necessary fields. However, having worked with cellular base stations at my last job, I will note my own feelings towards it.

The important thing with end devices and basestations (whether that is for a cell phone or a WiFi access point) is coverage and signal strength. If you place a device on the fringe of a coverage area the base station and the end device will have to use basically the maximum signal strength to communicate. The same applies if the device is placed right next to the base station. This is equivalent to standing next to someone and screaming into their ear. Another is if there is so much nose in the area. A good metaphor is to compare it to a school cafeteria with everyone talking. At some point, it gets so loud that you have to start talking louder and louder just to be heard by the person standing near you.

Regardless of risk for RF exposure, with 2.4GHz devices it is good to scan the environment now and then and make sure that you aren’t operating on a frequency that is congested. It will reduce the overall radio power output, and also make communication much smoother, faster, and use less battery power. :slight_smile:

With regards to “cooking”, which is something I am a little more worried about… Well, a microwave oven operates at about 800W or so, if I recall. My boss at my last job basically recommended NOT standing in front of our antennas when a base station was outputting at 50W (I also chose not to for the 10W configs). I did however routinely have a 100 mW desk unit on my desk. That didn’t worry me so much. I do know someone who was a broadcast engineer for KFRC/KMVQ/KYCY, and he told me that he would (crazy in my opinion) work around antennas that were transmitting (I forget the exact wattage he said). He’s kinda old and still alive, and this was in the '80s.

I’m not too concerned about devices in my apartment. I am only a little more mildly worried about constant RF noise that affects the health of an RF network; but not so much concerned about the power output being high enough to affect me.

That said… I don’t carry my cell phone in my pocket all day or talk on it a lot. I also don’t sleep next to my wifi router. If it puts off more than a few mW I try not to keep it “on” me for extended periods of time. In fact, keeping it on a belt clip is something I have considered instead of in a pocket (though my belt at the moment is kind of overloaded). As for cell phone base station antennas, the common set used by a cellular carrier is a sector antenna (they cover a varying degree, usually from about 60 degrees to 120 degrees). They are directional. So usually if you are behind it, you won’t get blasted. This is a good visualization (though it doesn’t have a “heat map” that would show signal strength at an optimal layout):


By contrast, and omnidirectional antenna (basically a pole – this is more commonly seen with transit and emergency setup, as well as TV and radio, but they tend to be up on taller towers for better coverage) would be a (lumpy) circle centered over the center of the graph on the horizontal graph.

Anyway, I realize that may be a bit scattered. But those are my feelings on the topic. (My irrational fear around this, though, are the full body scanners. But I think that is more of a “why are we doing this stupid bs?” thing. But, this is another topic not for here. :slight_smile: )


#35

yup, or this:

or that:

ok, this is about cell phones, which emit a maximum of 200mw (usually much less) when on LTE. Philips Hue has an output of about 3mw per bulb.

That said, it’s funny how people always say Wifi is harmless compared to mobile phones because the latter have higher power output. That’s not really true anymore. A phone will very rarely output 200mw - usually they’re at a fraction of that, well below the 100mw that are emitted by WiFi base stations. And a Hue bulb some 40cm away isn’t any better than a wifi base station 5-6m away. Radiation exposure is about the same. So the question still remains how constant blanket exposure emitted by a Hue- and WiFi-equipped home will influence the human body. Personally I think it’s a pity that Philips has chosen the 2.4ghz band that doesn’t have any duty-cycle limitations. Z-Wave 800mhz devices emit dramatically less EM radiation than 2.4ghz band equivalents. Unfortunately, Z-Wave seems to have lost the standards war.