Count Accumulator For Radiation Levels


This hack was put together by reader [Forrest Cook]. He was wondering if there were any radioactive materials in his rock collection. This is an add-on box for a 60s era Victoreen CDV700 Geiger counter. Vintage gieger counters don’t actually count; they use an analog meter with an integrator circuit to do short term averages. Forrest’s box plugs into the headphone jack of the Geiger counter and does true digital counting with a Motorola microprocessor. The signal could also be sent to a computer with a little modification. He did find a handful of radioactive rocks, but nothing that was serious enough to worry about.

11 thoughts on “Count Accumulator For Radiation Levels

  1. RE #7 “cool”dude WHY in your ever so vaunted opinoin, is this a STUPID hack? Too simple? Too easy? Too… not interesting to you and therefore must = stupid?

    Seriously – ENOUGH with the derogatory comments – they don’t help ANYONE who reads or posts to this list.

    Last year in my digital electronics course one of the groups decided to build essentially this same thing out of discrete logic components. Worked fairly well, but the number of components they had wired together was insanely high compared to this micro-controller based approach.

  2. Yep, microcontrollers are great like that. I felt a little sorrow a while back when one of the guys who was instrumental in their design and creation died. Without this technology, we would still be in the technological dark ages.

  3. Am I the only who read “his rock collection” and thought about his Rolling Stones and Led Zeppelin albums etc.?

    Off course, real rocks have radioactivity sometimes, but hey it’s early in the morning on monday soooo……

    – Unomi –

  4. I’ve done stuff like this for the CDV700 counters (and others), however with the advent of the (free to use) CDVcounter software, there is no point any more – no modification of anything is required to get much better results on computer, you just plug the geiger counter’s earphone jack directly into your computer (or better, laptop) soundcard mic port, and it does graphs, web server stuff, etc.
    Plus, you can export the data to excel or other programs to do more complex analysis.

    That’s not to knock this hack though – you should do stuff like this yourself at least once before having a premade solution handed to you :-)

    I recommend CDVcounter though, it’s simple but interesting to play with. If you have two geiger counters, you can rig up a stereo adaptor and make a cosmic ray (muon) telescope.

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