posted 5 years ago
Thanks, that looks like a useful link (except it doesn't mention high altitude as one of the common reasons for low blood oxygen, hahaha!). I've bought those at CVS in the US.
I dunno about those normal levels, or maybe ours was too cheap and unreliable. When we tried it on all our students (native to high altitude) and visitors and volunteers (native to low altitude but acclimatised to high), the oxygen levels of people who felt perfectly fine ranged from 83 to 97, if I recall correctly. So I agree, it's probably most useful if you take readings a few times when you feel healthy, and keep a note of those, to compare with if and when the person ever seems to have a respiratory problem.
Works at a residential alternative high school in the Himalayas SECMOL.org . "Back home" is Cape Cod, E Coast USA.