Hi James,
Regarding the post from Wednesday about the old rad meters for $60, they were about the only thing easily available before Y2K. At that time the conventional wisdom, (which I am almost certain goes back to Bruce Beach, since he was selling piles of old Canadian ones for 50 bucks) is that the ionizing chamber can deteriorate over time and to be safe you must multiply by a factor of four when using it. If it reads 5 R, figure it is 20 R. If it reads 20 R, figure it is 80 R. This should definitely keep you safe.
By the way, Shane at ki4u.com calibrates rad meters and the turn around time is currently 10 days. See here: http://www.radmeters4u.com/calibrate.htm
Shane has said in posting at the doomer-prepper forum www.timebomb2000.com that if you carry a rad meter in your car where it gets heated, frozen, and bumped around, it should be recalibrated yearly.
By the way if your readers are not familiar with Nukalerts, they are a great little gadget.
God bless, – Lyn
JWR Replies: I agree that recalibration is a good idea. Also keep in mind the radioactive decay of test sources. If your test source is tritium, since tritium has a half-life of 11.2 years, then obviously if your test source is 11 or 12 years old then your meter will only indicate one half of the reading versus a fresh test source.
I also agree that the NukAlert is a great product. They are available from Ready Made Resources and several other vendors.