Message posted by lone wolf on November 22, 2006 at 0:10:38 PST:
I have I got it from ebay untested. The cable was missing, hence not possible to test. I ordered a cable from Ludlums and I lucked out that it worked. I haven't calibrated it, but I did compare it to a working unit at the NTS "reading room." The readings were close enough for government work. I think by the time the dust settled, it cost $150. If you expect to read background levels, you need the 0.1x scale, which generally the CD units don't have. My understanding is the CD units will still "click" with hit with particles from background radiation, but it will be hard to read the value. All the meter does is integrate the clicks per minute which somehow converts to R/hr. The sensor shown has a gamma shield. That is, with the shield in place, you read gamma. With the shield open, you read gamma plus beta. Some geiger counters have the sensor in the case rather than on a cable. I've seen the CD type for sale at the local flea market for about $40, sometimes less. Some use funny batteries. Well, I should point out that was at the Livermore flea market, which tends to have odd items. If you luck out and find a meter that you can test first, a simple source is a Primus latern mantle. You need to get one with the radiation warning label on it. You can also just order those uranium "marbles" that seem to be on ebay all the time. I don't want to put an ebay ad in the forum, but a search on uranium marble on ebay will lead to a good deal, and funny, it comes from Oak Ridge. ;-)
http://www.ludlums.com/product/m3.htm
with
http://www.ludlums.com/product/m44-6.htm
My recollection is you are in Vegas. I see an old CD geiger counter for $10 on Craigslist.com. The guy has 30 of them, so I bet he has a source handy to prove it works.
In Reply to: Re: Background Radiation? posted by Gregos on November 21, 2006 at 22:12:22 PST:
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