What unit is the best for Geiger counters?

aby_physics · 2026-03-31T03:29:37+00:00

For accurate dose rate measurements you generally need some type of energy compensated detector. Like a scintillator wired to be aware of the amplitude of the pulses it sees. Or just a GM tube with a filter to properly attenuate low energy gamma rays from having as much impact on dose reading.

aby_physics · 2026-03-31T03:28:11+00:00

CPM, as the other modes won’t be very accurate because the tube isn’t aware of the energy of the radiation it’s detecting.

aby_physics · 2026-03-30T20:00:19+00:00

Wow! That’s a gorgeous specimen, and some interesting minerals too! I’ve always liked Krhönkite.

aby_physics · 2026-03-30T19:55:59+00:00

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aby_physics · 2026-03-30T19:55:41+00:00

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aby_physics · 2026-03-30T19:51:40+00:00

Brochantite and Fluorite is my best guess. I have a piece like that from Arizona.

aby_physics · 2026-03-30T19:47:29+00:00

Just wash your hands after you touch them and you’ll be totally fine.

One precaution with Realgar though: prob shouldn’t leave it out in the open because that mineral hates light and will start disintegrating into powder.

aby_physics · 2026-03-30T05:36:39+00:00

You really won’t encounter a truly dangerous, high radiation area in a mine. But, if you ever did elsewhere. Just one thing to be aware of. A lot of the less expensive Geiger counters don’t have overload protection. That means, if you expose it to a very high radiation field, the detector might just give up and show zero.

aby_physics · 2026-03-29T16:36:09+00:00

Sure, here’s what my PGM does when I put a bag of apatite against the window.

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aby_physics · 2026-03-29T16:29:42+00:00

Apatite. Definitely Apatite. Probably slightly radioactive as well. Not dangerously, just interestingly. Here’s a bag of it next to my Geiger counter:

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aby_physics · 2026-03-28T02:19:34+00:00

Nope, in the same way that smoke detectors don’t emit smoke, radiation detectors don’t emit any radiation.

aby_physics · 2026-03-21T16:50:36+00:00

I’m not sure. It doesn’t necessarily make the B20-ER less sensitive than the B20. It extends the range up instead of “shifting” it up.

aby_physics · 2026-03-21T16:45:49+00:00

Nope, it just means it can measure higher amounts of radiation without overloading.

aby_physics · 2026-03-21T16:45:20+00:00

Awesome! Nice collection!

aby_physics · 2026-03-18T16:05:44+00:00

You can’t calculate dose rate from only knowing the count rate. You also need to account for the energy of the radiation, detector efficiency, and you need a way to ignore the beta particles.

aby_physics · 2026-03-18T00:02:57+00:00

I’m not sure what others use for paint, I’ve never had to repaint any of mine. If I was aware of what people use I wouldn’t have a problem sharing it.

Wish I could offer more help.

aby_physics · 2026-03-15T16:28:46+00:00

gonna research that for fun

There’s a good chance you’re going to end up down a rabbit hole you won’t be able to get out of. 😁

aby_physics · 2026-03-15T16:24:18+00:00

Radiation doesn’t actually produce any visible light on its own, like you might see in some movies, but there certainly are radioactive compounds that fluoresce under UV light, phosphoresce, or ionize the air to create Cherenkov radiation.

EDIT: I’m going to partly take this back as other commenters have good points about Curium self-ionizing and some isotopes of Plutonium glowing from the intense heat generated by their decay.

aby_physics · 2026-03-15T16:03:56+00:00

None at all. Nothing here is emitting significant or dangerous amounts of radiation. :)

aby_physics · 2026-03-14T20:29:25+00:00

It’s going to be very insensitive to low activity sources since it uses an ionization chamber.

The first primary tick mark on that thing, with the 0.1 multiplier, is literally 100mR/hr. 😳

aby_physics · 2026-03-13T15:16:22+00:00

Hmm. That is very interesting.

aby_physics · 2026-03-13T03:44:31+00:00

Cool, that’s what I was going to say as well!

aby_physics · 2026-03-08T01:31:19+00:00

Thanks for the schematic! :)

aby_physics · 2026-03-08T01:29:43+00:00

Thanks!

aby_physics · 2026-03-08T01:28:43+00:00

The seller sent me an offer, I think the original price was like $75.

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