this post was submitted on 13 Sep 2023
112 points (79.2% liked)
Technology
60048 readers
2912 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
It's not per kilogram of the device. It's a measure of absorption per kilogram of body mass of the person using the device.
A good way to think about it is: throw a small piece of meat into the microwave and let it absorb some microwaves. It gets warm. Now imagine a much larger piece of meat. It can absorb a lot more microwaves before it starts getting warm. The smaller the 'body mass', the less radiation it can absorb and dissipate before becoming damaged. So when it comes to mobile device radiation levels, they focus on the watts of radiation absorbed per kilogram of body mass.
and different parts of the body resonate at different frequencies...~~part of the reason ~2.4 GHz was picked for the common household microwave is water molecules resonate there~~ (and other harmonically related frequencies too... it's why a lot of the unlicensed ISM stuff is allocated there: crappy atmospheric propagation). also the necessary magnetron and waveguide for that freq is conveniently sized for a kitchen appliance and not too complicated.
EDIT: see proper principle of operation in reply below