Measure Radiation With Military Surplus

It’s really amazing what you can find at military surplus shops. [David] just built a radiation detector out of a DT-590A scintillation probe originally made to test if Air Force bases were contaminated with Plutonium. Who says nothing good came out of massive nuclear arsenals?

DT-590A / PDR-56 Gamma ray probes were made obsolete by the US Air Force a few years ago and they’re trickling into military surplus stores around the country and the Internet. [David] found the manual for this probe and put together a little circuit to drive this x-ray sensor. The build uses an ammeter as a simple dial, and includes a piezo speaker for the prerequisite Geiger counter ‘clicks.’

[David] also threw up a post on converting this x-ray probe into a general purpose Gamma probe, effectively making it a Geiger counter for the really dangerous radiation. You could always use your smart phone for the same task, but recycling military hardware imparts a good bit of geek cred.

13 thoughts on “Measure Radiation With Military Surplus

      1. i just checked its now only $70 from the same people

        the time and effort required to track down, strip, test, re-certify, package and reship the outdated tubes is far more than selling the ready built un-calibrated counters to hobbits who can easily recalabrate them, them selves
        wont pass the health and safety standards but works great for my projects

  1. The difference between gamma-rays and x-rays is their origin, not how dangerous they are. Gamma-rays are photons produced by nuclear decay; x-rays are photons produced by accelerating photons, for example by striking electrons into tungsten target in an x-ray set. Many years ago, gamma-rays were higher in energy (and more penetrating) than could be achieved with x-rays, but nowadays linear accelerators easily achieve x-ray energies far higher than gamma-radiation.

    The damage caused by ionising radiation depends on the amount of energy deposited multiplied by a quality factor that depends on the type of radiation (photons, alphas etc.). Gamma and x radiation share the same quality factor. Higher energy photons are not necessarily more damaging than lower energy, it is just that their energy is deposited over a different volume of tissue as they are more penetrating.

  2. For anywone interested in doing gamma spectroscopy: Look for Bee Research GS-1100A or B, it’s an USB interface to drive scintillation probes and output audio pulses which can be analysed by software (freeware and open source software available for this purpose). It’s also far cheaper than buying bulky multichannel analyser hardware.

    BTW, anyone know what the advantage is of a scintillator probe over a geiger muller tube? If you want to count pulses it seems that it’s easier and cheaper to get a GM tube. With some shielding they will only detect gamma.

  3. Some tubes have quite a sharp “knee” above which they are totally unstable,
    this can be rectified by varying the inline resistance, some tubes “like” lower than 2M2 while others seem to work best with 10M or even 22M.

    Discovered this the hard way after my SBM11 tube was nearly discarded as “bad” when it was caused by voltage instability and possibly a resonance between count rate and Vtube.

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