Geiger Counter Fun

[Answerprancer]

Has anyone here had any fun with one of these?
I bought one recently and did some exploring with it...

Background radiation where I live: average 0.1 microsieverts/hour

'vaseline glass' sugar bowl I have: 0.8 (the glass contains uranium oxide)

Background radiation on a recent flight at about 30,000ft: 4.0!

Takumar 50mm vintage camera lens: 24.0!! (the glass contains thorium)

Porst 55mm lens: 20.0 (thorium again)

Vintage mantle-clock with luminous hands/dial owned by me Mum: 7.0

Also I got a higher than normal background radiation result walking under an old red brick railway bridge recently - which was odd.

[jomifl]

https://xkcd.com/radiation/

This puts radiation doses into perspective.