Turn your camera phone into a Geiger counter | Hacker News Reader

Turn your camera phone into a Geiger counter

hackaday.com

125 pointsbcl27 comments

I wonder how plausible it'd be to make a little spinthariscope[1] attachment to stick over the camera instead. Rather than affecting the CMOS camera element itself, you generate visible light flashes with a fluorescing capture material.

[1] https://en.wikipedia.org/wiki/Spinthariscope

If you dig this, you'll want to check out Safecast.

Safecast (http://blog.safecast.org/) is "a global sensor network for collecting and sharing radiation measurements to empower people with data about their environments." They are working on some really awesome tech and helping people in Japan.

Direct link to Rolf-Dieter Klein's site: http://www.rdklein.de/

Says there's an iOS version awaiting approval.

You think it will be approved? Doesn't this app somehow encourages damaging your phone?

So this is the CMOS equivalent of the astronauts whose retinas are bombarded by cosmic rays? Neat stuff.

Do elaborate on astronauts and their retinas. I haven't heard this one before.

Man, I'm no expert here and I'm typing from memory but I'm pretty sure that astronauts experience retinal sparkles/flashes that are caused by particles that we're shielded from normally by our lovely planet. The particles hit the retina and trigger the perception of light. I'm sure that ultimately it's not a healthy thing.

Keep this in mind when we are all flying off to Mars or, you know, wherever.

At which point it will probably be touted as a reason for going to Mars.

I can see it now... "Go to mars.. and see the stars!"

Thought that was for Jupiter.

http://www.spacedoc.com/retinal_flashes.html

Very neat. I work at a cancer center and I've noticed a very similar effect on the CCTV at the operator console of the linear accelerators (the camera is inside the bunker).

Note that the speckled image in the post shows the result when exposed to 10Sv/hr. 1Sv makes you sick, 10Sv is virtually guaranteed to be fatal.

A minor nit pick: a 10Sv whole body dose is very likely fatal.

Routine cancer treatments are in the 20-80Sv range delivered in fractions of 2Sv.

During stereotactic radiosurgery (e.g. for a brain tumour) a patient can receive in the neighbourhood of 50Sv in a single fraction.

I am convinced that we actually had the idea first and built the first prototype for this. Sadly, my companies bureaucracy held up the release of the application. I even wrote a blog post about it a while back...

http://spoiledtechie.com/post/2011/09/12/Fucking-Big-Company...

Yeah, that is one of the problems of working for a large company. If its any consolation one of the reasons that pushed me into leaving Google was they had this horrendous "we own any App you write for a phone" clause in their employment agreement.

It would be interesting to know how your company would react if you quit and decided to market this product.

"we own any App you write for a phone"

Does this refer to apps written on company time or using company resources? Or any application written for a phone from anywhere at any time?

Their interpretation (and I got this directly from HR/Legal) was that any app, for any kind of 'smartphone', even if it was on your own time on all your own gear. They claimed that Google was in the business of 'smartphone applications' and so anything you wrote belonged to them. Even in California. I asked them if I wrote a kitchen timer application for the iPhone would they claim ownership, they answered in the affirmative.

And I did consult an attorney on that and his comments were that you could probably litigate it and win, although you would wouldn't be working there any more. So if you really wanted to write an app, just quit and write it, so much simpler legally, and you could keep all the profits rather than run the risk of losing all the profit and ownership to Google.

> This product is soo revolutionary, it has the ability to put an entire product out of business

Is it accurate enough and sensitive enough to really replace geiger counters (assuming that's what you are talking about)?

It is actually.

The algorithm is soo brain dead simple too.

Related - endoscopic probe into the Fukushima Nr.2 reactor shows radiation artifacts: http://www.smh.com.au/world/first-glimpse-inside-fukushima-r...

Could you stick a smoke detector in a smoke-filled bag with the americium pulled out to make a geiger counter?

If the camera is covered with tape, why can I still see the room in the image?

I don't think it's covered in that demo. At 10 Sv/h the effects are so immediately obvious that you don't really need to subtract the actual image.

Can anyone tell me how this is possible? Im vey dubious.

It uses the camera, which is triggered by the high-energy photons in Gamma radiation. That is why they need to cover the lens with something that only lets radiation through, but no light.

And presumably why it's pretty poor at discriminating Alpha & Beta, since they'll be quite easily stopped by the barrier as well (and probably the lens even if it were exposed)

IIRC actual radiation detectors use very thin mica films to protect the sensor, so they can admit the lesser penetrating particles.

I m going to try it on a banana http://en.wikipedia.org/wiki/Banana_equivalent_dose

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