Librem 5 SAR (or DAS)

Hardware Librem 5
41

Emanations then, picky, picky, picky.

42

I agree that radiation exposure should be minimal at the first place and @Caliga already covered basic advantages of Librem 5 when referring to “possibly sufficient space on the PCB to have good antennas”. One of good antennas solutions is usage of Metamaterial-Embedded Low SAR PIFA for Cellular Phone, covered with this statement: “The achieved SAR reduction by metamaterial is 42.12% and by Materials 47.18%,which provide information to design metameterial based antenna for minimize biological effect on human body due to EM radiation.” On radiation exposure of popular mobile phones specifically, professor Gert Frølund Pedersen presents in this study some measurements of total radiated power (TRP) … that includes free space (FS), Fig. 1(d) because “for most of the bands the introduction of a human hand increases the spread among the phones and it is around 5 dB”, etc. Qualcomm® 5G modem-to-antenna solutions are complex as well but head SAR and body SAR are just barely under 1.6 W/kg. We all expect good SAR values from Librem 5 and I am sure that those will be known with batch Evergreen (if not earlier).

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43

In France, a law due to come into force in July 2020 limits SARs to :

  • 2 W/kg for head
  • 2 W/kg for trunk
  • 4 W/kg for member

Test condition is 0mm distance between device and skin.

We are now at the Chesnut batch. Do you have any clarification on this very important point from a health point of view? Thank you.

44

ok but that is only the law it has nothing to do with actual real-world spikes in SAR values.

you enter a tunnel or some low signal area and your SAR will go up temporarily because it needs to compensate … some real world examples are in order (not the lab ones)

45

It’s impossible to measure SAR before the final design is available (batch Evergreen with moulded case).
But, considering the thickness of the Librem 5, it shouldn’t be a problem.

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46

Of course you are right, there is labs and real life conditions, but at “normal condition” (let’s say outside with good signal), I would be happy to know how much SAR I absorb (head, body). My fear is, as the L5 is not like other smartphones, the network module is in M.2 slot, and the design is different, so I hope SAR won’t be too high.

@Torrone I understand that it is better to get results with the final design, that’s a good remark.

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47

Here is some reference data. Best phone so far seems to be Samsung Note II, old but cancer-safe (0.17 head SAR), while iPhone 5 is 0.9. Newer iPhones are much higher, close to 1.6 max limit.
http://tawkon.com/blog/en/note_2_sar

Studies link SAR radiation to brain cancer unfortunately. Phone companies hide this info as much as possible but it is serious, so I hope Librem 5 takes a lead here, and gives us another major reason to buy it, in addition to privacy and security. Thank you


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48

thankfully I don’t do much calling

49

As the hardware design is complete and phones on the market - did anyone mesure the SAR of a Librem 5 evergreen? (with all switches to enable RF ofc :smiley:)

50

Wouldn’t you need access to a proper lab and such so the testing isn’t contaminated by other RF? I don’t imagine too many people have that access?

51

I know someone who lost his phone in the sand near Fort Hancock, Texas. I think his phone needs a little SAR (Search And Rescue).

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52

I suspect what has been written behind your first link to be methodologically wrong. It is impossible to be sure for a single specific case to tell if such a decease is caused by cell phone radiation or not. Even if it would be plausible, e.g. because it occurred at places that have been near to the cell phone. This could be coincidence and the real cause may be something completely different.

Maybe I missed something but as far as I know the only known effect of classical cell phone radiation is a moderate increase in temperature which is not necessarily harmful.

When more and more people bought their first mobile phone, let’s say between 1995 and 2005 it was not so clear if this technology is harmful or not. There was simply not enough data. Meanwhile there should be plenty of data.

You are right in that the mobile phone industry has conflicting interests in case they knew about significant harm from their products, so they might play the risks down. On the other side there are people that become obsessed by the irrational fear of the risks. And they are publishing to. Maybe some of them make money with it.

There is a famous anecdote from where I live. A major MNO installed a new cell tower. And people living nearby started to articulate new health problems like headaches and so on. And then the MNO published a statement like: “If it is already so bad now, how bad will it be when we finally activate the the cell?”

What we need is independent information, methodologically correct collected, analysed and interpreted.

53

Dear all,

I was wondering if there were having any news on the SAR of the Librem 5?

I have found nothing on the web site yet.

Thanks,

Patrick

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54

See the FCC report:

Librem5_SAR
Librem5_SAR857×790 106 KB

You will have to compare it to other phones to get an idea how well the L5 does on SAR. Generally Samsung phones have the lowest SAR, so compare to those.

3 Likes
55

The link to the report (search result) may not work, so navigation directions are:

I like how there are pics included of the measurement setup and all the variations. Report seems thorough and well standardized. Kinda explains why those take a little time to get done.

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