So, I finally got something radioactive, an old bullfinch mantle, complete with thorium and asbestos string.
Now, assuming my Geiger counter is reasonably accurate (last calibrated in 84 I believe, yes it is a bit out of date), this puts of at most around 4 milliroentgen per hour peak (when the meter is right against the thickest quantity of the mantle).
So, that converts to 34.78 microsieverts, and according to the xkcd chart, a flight from NY to LA is 40 microsieverts, so in effect, holding the mantle in my hand for 1 hour would expose said hand to just under the amount of radiation my whole body would experience in one flight.
Also, based on that, I think that I would need to hold the mantle in my hand for 1,437 hours to reach the safe annual radiation dosage for radiation workers, or 966 hours for civilians (at least in that hand)
Just wondering if someone can confirm I have got that all straight, or perhaps I made a mistake somewhere.
http://xkcd.com/radiation/http://www.convert-me.com/en/convert/radiation/I also want to make something with an arduino that can hook up to the headphone connector and count the clicks to calculate and give this information automatically, but I think that it might not work so well, or at least it would be a bit off, since it clicks quite rapidly when the radiation gets decently strong, I'm not sure if they might overlap to much to cause an issue. The "clicks" seem to max out about half a volt, and I'm curious what would be the best way to pick up those signals safely, without risk of 5v from the arduino being piped into geiger counter. Never dealt with opto-isolators before but that seems like a good start, I could also use pointers on how you go about turning a signal like that into an input, I'm not sure if it would be as simple as setting it up similar to a button. It's 5v dc so it wouldn't need an analog to digital converter I don't think, it does just make a piezo speaker click.
Pictures to make it a bit more interesting: