Interesting cellphone based radiation detector

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Joined: Wed Oct 19, 2016 3:28 am
Real name: Grigory Heaton
Location: San Luis Obispo CA

Interesting cellphone based radiation detector

Post by Grigory_Heaton » Wed Nov 23, 2016 3:15 am

I wanted to share this interesting application I tested out earlier this fall. It's an Android (and I assume iOS but I haven't looked) app that allows you to detect gamma (and probably higher energy beta) radiation using the phone's camera. ... vity&hl=en

I was surprised to find out from several videos (and later my own tests) that this wasn't one of the many fake "geiger counter" apps you find online. It works because gamma radiation will create a white spot on the camera view when it strikes the sensor, so by completely covering the camera lens you can shield all non-ionizing radiation and measure gamma radiation.

It's obviously going to be one of the worst radiation detectors you could possibly get, but it is incredibly cheap and it does kind of work: a $10-20 Ebay or prepaid phone and a couple layers of opaque tape is all you need. I got very dramatic results with a 1 uCi Am-241 smoke alarm source (emitting ~60 keV gammas) when the lens was pressed within a centimeter of the source.

Unfortunately their site is pretty out of date on what phones they have tested, so I wasn't able to actually calibrate it properly and test vs my real geiger counter, but even without a dosage reading you can still see large increases in radiation over background pretty easily with it.

If the source is strong (like the Am-241 one pressed right up against the lens) you actually don't even need to pay for the app, since every second or so you will see a white flash on the screen (so long as your camera is properly covered).

Hope this information is useful to someone.

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Richard Hull
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Real name: Richard Hull

Re: Interesting cellphone based radiation detector

Post by Richard Hull » Wed Nov 23, 2016 10:04 pm

I have a friend in the ANS, (American Nuclear Society), who works for Dominion Power, (North Anna nuclear). At a ANS meeting about a year ago, he showed up with this app on his cell and a 10uCi, Cs137 source. I was impressed, but we both realized, as noted above, you would be in a really nasty gamma field if this app was working for you. You could be in a near lethal beta situation and it would dummy up on you. We mused that a thin layer of lead foil over the CCD and a very hot beta source might make enough x-rays to see a beta source.

While cute and effective on intense higher energy gamma, it is not a true, useful, radiation detector.

Want a good detector setup? 1. Purchase a good pair of pen dosimeters and charger. 2. Purchase a good electronic ionization chamber meter. 3. Most important, purchase a good GM counter with a 2" pancake head. Armed with these three, you are covered from a massive nuclear exchange, should your survive, all the way to simply puttering around the lab having fun with atomics.

If you go uranium hunting, A good portable scintillator of the TSA type is the best item to have. It will find hot ore buried one foot under the dirt that a GM counter would never see!

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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