Prepping 101: $30 Geiger Counter for Android/IPhone – Works! (on Android) – Smart Geiger

Authors Paul Helinski Prepping 101

That little black bug sticking out of the phone is the Smart Geiger. This pic was from my first attempt with it, using the probe from the side. I got an active reading with this radioactive Thorium treated lantern mantle, but it was very low. Note that on IPhone 5S it didn't work at all though.

That little black bug sticking out of the phone is the Smart Geiger. This pic was from my first attempt with it, using the probe from the side. I got an active reading with this radioactive Thorium treated lantern mantle, but it was very low. Note that on IPhone 5S it didn’t work at all though.

Smart Geiger
Company website: https://allsmartlab.com/eng/SensorList.php
On Ebay: My seller at $29.90 +$5 shipping from S. Korea
All Sellers: from $29.95 shipped

We are all living in a potential radiation hotzone of the future. Radiation is silent, invisible, has no smell, and there is a good chance that we all will have to deal with radiation in our lifetimes. It could be, as NWO kingpin George Soros says, an all out nuclear war with China and Russia. It could just be that a few nukes pop a couple hundred miles in the air, using our nationwide electrical grid as a giant antenna to wipe out our power stations (an EMP). That would lead to a meltdown of our nuke plants plants all over the country, which need a power grid to cool themselves. If you think you are “prepping,” but you aren’t prepared to measure both high and low levels of radiation (two distinct issues), it might be time to take a look at your options.

For about a year now in this column, I have been searching for inexpensive radiation measurement devices that actually work. The problem with keeping the costs down is that the electronics to manage a true Geiger-Mueller tube are complex and expensive, and most Geiger devices only solve half the problem. My prior finds are still great options, but I recently found a $30 answer to at least the low level of the radiation measurement equation. The Smart Geiger device is made by a company is South Korea, and it relies on your phone to provide the measurement electronics. The little Smart Geiger bug plugs into your headphone jack, and on low level radiation I tested it and it works fine with a Samsung S3 running Android, though I found it mildly inconsistent. But I think it is good low cost option for testing food, water and living arrangements post disaster. IPhone 5S was a complete fail, but you could contact the manufacturer if you want to try for yourself. The only caveat I have to mention is that most likely, like all low level meters, the Smart Geiger could not be used as a “survey meter” to test for high level radiation right after an accident or explosion occurs. I’ll explain below.

This is the app in the Play Store. It is free in both the Google and Apple stores.

This is the app in the Play Store. It is free in both the Google and Apple stores.


Measuring radiation is a big source of confusion for most people, including me when I first started out. Alpha, Beta, Gamma? How much is harmful? Is air radioactive? Water? Food? Don’t they irradiate food? How are you supposed to measure radiation when you don’t know what it is?

As a little bit of background, when a nuclear bomb goes off, or a nuclear power plant melts down and explodes particles into the air, it creates a whole bunch of different radioactive isotopes. These are called “radionuclides.” You’ve probably heard of some of them, like Cesium-137 and Strontium-90. Those two are particularly dangerous long term because they have long “half-lives,” meaning that they last a long time in the environment as the radioactivity decays. We have heard all our lives that a place stays “radioactive” for 25 years after a nuclear bomb explodes, and it is these two isotopes that seem to pose the long term danger. The forests around Chernobyl for example, which is the nuclear reactor that exploded in 1986, have been on fire lately, and the smoke from the fires is dropping noticeable radioactive particles, tens of miles away. A whopping 29 years later the particles are not causing dangerous levels of radiation to stand next to, but ingested they can do serious harm.

Radiation gets really confusing really fast. This explains the differences between Alpha Beta and Gamma. It is taken from the FEMA pub "Radiation Safety in Shelters" from 1983, (linked PDF in the article). What you really need to know is that radiation is in the air, and because there will always be Gamma if there is Alpha or Beta, most meters will cover you.

Radiation gets really confusing really fast. This explains the differences between Alpha Beta and Gamma. It is taken from the FEMA pub “Radiation Safety in Shelters” from 1983, (linked PDF in the article). What you really need to know is that radiation is in the air, and because there will always be Gamma if there is Alpha or Beta, most meters will cover you.


Short term serious danger, right after an explosion, comes from dozens of other isotopes that are blown outward. Many of them have short half-lives, so the first 48 hours after a nuclear event is most critical to stay indoors, or ideally in some kind of shelter that has heavy material between you and the radiation. I have included a chart of various materials 1983 FEMA pamphlet “Radiation Safety In Shelters,” which you can still download for free in PDF format in many places on the web. Radiation attenuation is directly proportional to weight. So 200 lbs. of wood will insulate you just as well as 200 lbs. of lead. The only exception to this is a substance called Barite, commonly used by commercial drillers to weight down the drill site. It has shown unusually high attenuation of the radiation emitted by Cesium-137, and Barite is often mixed with cement for containment walls at nuclear power stations. It is also really really heavy for its size, but I haven’t been able to find a cheap source for it in the Southern US. Just remember that it is all about weight, so bags of cement mix, which will be great trading fodder after the world gets back to normal, are much better than bags of sand, but if the sand is free, it’s just as good as cement. Just make it thicker.

If you can survive in a sheltered location for the first 48 hours after the initial blast, most of the particles have very short half lives, and they weaken considerably as time passes. Remember the 7/10 rule. Every 7 hours, there is 10x less radiation, from all radionuclides, and many of them die off completely. For example, the biggest short term killer, radioactive Iodine-131, has a half life of 8 days, so most serious preppers have Potassium Iodide (KI) pills in their survival kits. If you take the KI for two weeks, it will protect your thyroid from absorbing the radioactive iodine, and you’ll be fine. After Chernobyl, Poland gave all of their citizens KI. Ukraine did not, and while the Poles have been fine, the Ukrainians, Russians, and other surrounding populations have had to deal with terrible thyroid disease, cancer, and lots of fatalities.

Radiation sickness starts at about an accumulated dose of 50 Roentgens in a short period of time.  Just to give you a scale perspective, 1 Roentgen per hour would equal 10,000 uSv per hour. So when you see even 50 uSv. on a low level meter it's really not a damaging amount of radiation.

Radiation sickness starts at about an accumulated dose of 50 Roentgens in a short period of time. Just to give you a scale perspective, 1 Roentgen per hour would equal 10,000 uSv per hour. So when you see even 50 uSv. on a low level meter it’s really not a damaging amount of radiation.


“Radiation sickness,” where the body starts to break down immediately and death approaches quickly, is caused by both long and short half-life isotopes in that first initial period. They are extremely intense. For this initial period, you need a high level meter. I recently reviewed a $750 meter that covers low to high, but you don’t have to spend that kind of money for pure survival right after a nuclear event. I personally carry a $145 original NukeAlert keychain detector. Each unit is individually calibrated, and it makes little clicks to let you know that the battery isn’t dead. On the back there is a list of chirp levels to tell you how much radiation is in the air. But believe it or not, you can get basic knowledge that a radiation event has occurred, and basic information as to how much radiation you have absorbed for only $5.50. The same company, KI4U.com, that makes the expensive meters also makes these simple little stickers. We even ran an article not too long ago offering a free rad sticker that has a little bit of shelf time on it. The stickers are dosimeters, showing an accumulated dose, so eventually they get used up by background radiation. Even the free ones will tell you that something is going down if all of a sudden the line is visibly creeping fast.

The particles ejected by the blast will emit “Gamma” radiation, and “Alpha” and “Beta” particles. This is usually about 25 miles initially, but wind and clouds can carry the particles hundreds of miles away, creating “hotzones,” and nowhere is safe, except under some very heavy stuff. In the case of a meltdown, radiation would also of course emanate from the nuke plant site as well, but that range is fairly short. Your high level meter will let you know when your zone is free of serious radiation, and it is safe to go forage, or move to a safer location.

Background radiation is about .10 uSv where I live, and the phone bug meter measured that accurately.

Background radiation is about .10 uSv where I live, and the phone bug meter measured that accurately.


Low level meters like this $30 phone bug are what you call “Geiger Counters,” and they are equally important to long term survival. You need to eat and drink, and while the overall radiation where you locate may be low, there is no guarantee that food and water you are offered will be radiation free. After Chernobyl, the Ukrainian government covered up the effects of the meltdown for over 3 years. Doctors were forbidden to attribute illness to radiation, and there was so much disinformation that radioactive food from Ukraine even made it to US shores.

This is where the opposite is true. The yellow “survey meters” like the CDV-715/717 meters you can find cheap on Ebay (don’t pay more than $50 right now) are high level meters and they won’t tell you if food is radioactive. Neither will the keychain NukAlert, or the RadSticker. Those cardboard tube dosimeters don’t work either, and yes, I’ve tried them. You can buy a Thorium treated gas lantern mantle on Ebay for about $5, and they make great test subjects for low level meters, including the DIY kits I tested, the yellow CDV-700 with the wand (pricey on Ebay don’t waste your money), the SOEKs meters, the American made SBM-20 meters, and this $30 phone Geiger.

When I figured out that you had to point the flat part of the probe at the radiation source, the Smart Geiger spiked up to a respectable 22 uSv.  Both bugs worked equally as well.

When I figured out that you had to point the flat part of the probe at the radiation source, the Smart Geiger spiked up to a respectable 22 uSv. Both bugs worked equally as well.


The only meter that I know of that will measure both high and low level radiation is that $750 meter. It uses a Geiger-Mueller tube, with a new technology called “time to first count.” The low level meters, and regular Geiger tubes, saturate very quickly in high radiation fields, making them useless in that initial phase. Most low level meters will just crash. But that new $750 meter works great, at a relatively higher cost of course. Please note that if you get a CDV meter for high level radiation measurement, keep in mind that most of these date back to the 1960s, and they need to be calibrated. You can win the Ebay auction and send the meter directly to Shane Connor at KI4U.com and they will do the calibration(he makes that $750 meter too). Don’t wait until nuclear war is imminent. Meters are cheap right now and there is very little wait to get it calibrated.

Now for the $30 Phone Bug Meter

I would be remiss if I didn’t include and re-include the information that I gave you above. But now it is time to get to the subject at hand, this cool little $30 phone Geiger counter.

Let me start by saying that I am a big fan of using the smartphone as a universal electronics platform in a survival situation. I covered a network free GPS map system months ago, and besides a basic compass, flashlight, and easy entertainment for the kids, this Geiger is yet another cool survival use for you Android phone. I am not concerned that they can track me with it. I have seen how much backup fuel to power the cell towers they have in those pens and it ain’t much.

My expensive paddle Geiger measured the mantles at about 10 mR/hr, which is about 100 uSv/hr. The bug wasn't spot on, but it recognized a hot material when it saw one.

My expensive paddle Geiger measured the mantles at about 10 mR/hr, which is about 100 uSv/hr. The bug wasn’t spot on, but it recognized a hot material when it saw one.


Smart Geiger seems to be the first of several detectors that this South Korean company is adapting to the headphone jack of smartphones. At first I thought that this product was something of a dud, because as you can see from the pictures, I was measuring from the side, because it just kind of looked like the way you do it, and there are no actual instructions in English. Then I sat down to write this review and I said hey, maybe I’ll try it again. This time I just happened to point the bug directly at the Thorium mantles, and the phone meter spiked very quickly, for both bugs that I purchased directly from South Korea.

I think it is really just one seller on Ebay selling from several accounts, and they were very quick to answer and offer a replacement when I complained that one of the bugs didn’t work. Initially, before I figured out that you had to use the flat front of the bug, one of bugs was at least reading up to about .9 uSv, as opposed to the background level of about .1 uSv you see on pretty much all meters here in South Florida. The other bug seemed to be dead. Then I tried them both again, and they both rocked.

The Smart Geiger should pick up Beta radiation from Sr-90, which is often found in produce where the groundwater is contaminated, but it may only detect Gamma radiation. Strontium is in the same row as Calcium in the periodic chart, which means that it settles in bones. Cesium-137 settles in glands, like Potassium which is in its row on the chart.

The Smart Geiger should pick up Beta radiation from Sr-90, which is often found in produce where the groundwater is contaminated, but it may only detect Gamma radiation. Strontium is in the same row as Calcium in the periodic chart, which means that it settles in bones. Cesium-137 settles in glands, like Potassium which is in its row on the chart.


So I may be actually getting a free of these bugs, because their English isn’t so good, but to date I have not gotten any reading at all on the IPhone 5S, so I don’t feel too bad. It is supposed to work on IPhone, but though the app does detect the bug, the Thorium mantle shows no reading.

The term uSv means micro-Sieverts, which is a relatively new term in measuring radiation. The Roentgen, or Rad, Rem (R), is mostly interchangeable in a non-scientific context, and 1 Sievert equals 100 Roentgens. So, to simplify the math, to convert from uSv/hr to Roentgen per hour, you move the decimal 4 places to the left. 22 uSv, which I eventually measured my Thorium mantles at with the Smart Geiger bug, equals .0022 R/hr, or 2.2 milliroentgens per hour (1000ths/R, which eats 3 of 4 zeroes). There is a simple calculator online you can use if it gets confusing.

This is a chart of common building materials and how they attenuate radiation from that same FEMA pamphlet. It's all about weight.

This is a chart of common building materials and how they attenuate radiation from that same FEMA pamphlet. It’s all about weight.


For this reason, I still would not say that the Smart Geiger is a definitive meter. My $600 paddle Geiger counter counted the Thorium mantles at about 10 mR/hr, which is almost 5 times what the bug measured. I later returned with the bug again to the mantles, and couldn’t get it to go over 4 uSv, so take that for what is is worth. My DIY meters won’t go over 10 uSv.

But don’t take that as discouragement to not buy this ridiculously cheap product that works. As soon as the bug got within an inch of the mantles it flashed red on the phone, even from the side, on the weaker bug. If your food has radioactive particles in it, this meter is going to pick up something emitting Gamma. For food that is grown in a field that has Strontium 90 contamination, this meter will not pick it up, because according the radionuclides page on Wikipedia, Strontium-90 emits only Beta radiation. This bug is based on PIN diode detection technology and only picks up gamma and x-rays. Geiger tubes do pick up Beta, so if a regular meter is sensitive enough, even a regular SBM-20 tube should pick it up. But asking around to my nuke peeps it looks like our DIY meter is not going to be sensitive enough.

I think the Smart Geiger is an absolute nobrainer if you own an Android phone. It is durable, and it works. Buy it now before we get the next nuke scare, when they will be gone gone gone.

I think the Smart Geiger is an absolute nobrainer if you own an Android phone. It is durable, and it works. Buy it now before we get the next nuke scare, when they will be gone gone gone.


Strontium-90 is a particular concern because it is highly soluble in water, and it doesn’t kill a plant that absorbs it through its roots. The plant grows, and if you eat it, your body will absorb the Sr-90. If you look at the Periodic Chart of Elements, Sr-90 is in the same column as Calcium, which means that it exhibits the same traits, settling in the bones. Cesium is in the same column as Potassium, and therefore Cs-137 is particularly damaging to the glandular system.

For regular readers of this column, I know that I have been harping on the radiation meter thing quite a bit, and hopefully you already got your CDV survey meter and had it calibrated, or you bought the keychain NukAlert (I did both). The low level meters I have found are mostly very inexpensive, and if you use an Android phone already, I would buy one of these bugs as a backup regardless. Your phone is pretty durable. The bugs are pretty durable, and you can charge your phone with small solar folding solar panels available for cheap cheap. Maybe I use the term “nobrainer” a little too much, but if this isn’t a nobrainer I don’t know what is.

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  • Bryan May 3, 2018, 8:36 pm

    “Time to count” is not new technology, it is wrong technology. The number of counts in a time interval conforms to Poisson statistics. For large numbers of counts this resembles a normal distribution. The conventional practice is to monitor the background count rate and set the alarm level higher. In this case the number of false alarms and missed alarms may be estimated. Schemes such as “time to count” will produce much higher false alarm rates.

  • Gene July 7, 2017, 5:34 am

    Hi,

    Just dropped by to say thank you for this article. I was considering this inexpensive counter and this article made me buy one. Funny thing is I looked up my country’s (Romania) regulations for handling nuclear/radiation detectors and it appears I should get a permit from them! Well f**k that, I found a seller within the EU and I will get this SmartLab.

    Take care!

  • Android geiger counter July 30, 2015, 5:55 am

    i’m maurizio from italy, i make a true very small geiger counter for android device that detect beta and gamma rays from 0.01 to about 500 uSv/h. Please see this video. https://m.youtube.com/watch?v=bf_tJtTrk7A

    • Otto C Kiehl March 23, 2016, 7:33 pm

      I am interested in your Geiger counter for Android. If you have any information in English, please send it to me.

      Grazie,

  • Mike S June 10, 2015, 7:58 am

    George Soros and the NWO is a bigger threat to this country than either China or Russia.

  • Nuclear Tech June 9, 2015, 9:51 pm

    Actually shielding of radiation is much more complicated than just mass of material in between you and the radiation. Granted any shielding is better than none. Shielding gamma and x-ray is better with high Z material, materials that have high atomic mass. Shielding beta particles is best with low Z materials due to bremsstrahlung radiation created when beta particles interact with high Z material. Neutrons are best shielded with materials with high hydrogen content. Also, you have to consider the energy of the radiation to shield it effectively. Cs-137 emits a 662 keV photon/gamma ray so it is best shielded with high Z material such as lead, tungsten or concrete, all materials that are either high Z or high density. Strontium 90 is a beta emitter that needs to be shielded first by a low Z material such as plastic or aluminum then with higher Z or higher density materials. The next thing that complicates shielding radioactive materials are the daughter products of radioactive materials that are themselves usually radioactive. Case in point is that Strontium 90 decays to Yttrium 90 which also decays by beta emission to Zirconium 90 which is stable or not radioactive. Also complicating matters is the fact that several radionuclides decay by more than one mode. The last radioactive decay that I have yet to touch on is alpha emission. Alpha particles are stopped by a sheet of paper. Low energy betas can be stopped by the first few layers of your skin. Higher energy betas can penetrate your skin. Beta and alpha emitters are more damaging when inhaled or ingested into the body.

    • Administrator June 10, 2015, 9:08 am

      You didnt answer the question of whether a regular soft beta tube like an sbm-20 or this phone bug which is probably an sbm-21 will detect absorbes sr90

      • Chris June 10, 2015, 7:30 pm

        Very likely a PIN diode based radiation detector. This is why it’s not so good at detecting beta (or alpha).

        • Administrator June 10, 2015, 10:39 pm

          Yes, it is a PIN diode I have recently discovered, and does not detect beta. Very few tubes detect any alpha at all because alpha particles are not strong enough to even penetrate a piece of paper, let alone an enclosure of any kind.

          • Chris June 11, 2015, 1:35 am

            Yes but remember your pancake probe is great at detecting alpha – so keep that one around. It’s an industry standard and probably got one of these LND tubes inside. These tubes cost around $150 to replace if you pop it. Don’t know if links work here but here’s a link to see them: http://www.lndinc.com/products/category/2/

            I personally have an LND 7311. Most of those tubes will be similar in performance. Lower voltage ones have slightly more dead time so not as great at really high CPM, but still great tubes.

          • Administrator June 11, 2015, 8:44 am

            Yea the LNDs are pricey, which is why it is difficult to make a project with them for this series. The radiohobbystore.com guy and I have been conversing and he has a new board that will drive pancake probes with up to 15 feet of cable with no falloff.
            https://www.youtube.com/watch?v=1HU0H7GXIzA
            I’m getting a couple boards from him to try a low budget pancake project using a russian sbt-11a.

  • yodar June 8, 2015, 2:04 pm

    GOLDMINE-ELEC.COM Has Geiger Tubes and pwb semi-sassembled “kit” makins for not too modest costs http://www.goldmine-elec-products.com/products.asp?dept=1468

    • Administrator June 8, 2015, 2:43 pm

      In general the Goldmine kits are overpriced and don’t work because they don’t use plated boards for anything. The DIY kit from the previous articles here, from RadioHobbyStore.com are plated boards at a fraction of the price, and they use the SBM-20 tube that is most common for sale cheap online. You can also get the kits in soldered form for all of $12 more. I would not buy the Goldmine kits, for anything. I used to be a customer until I tried to make their boards with my kids.

  • Listener June 8, 2015, 1:57 pm

    I will assume this detector and app would still function if cell towers are out of commission? And assuming of course the phone is charged. Is this assumption correct?
    Thank you in advance Administrator for your reply!

    • Administrator June 8, 2015, 2:34 pm

      Yes the article says that it works without a network.

  • Chris June 8, 2015, 1:56 pm

    Paul, just a heads up – it’s a common problem and I was guilty of doing it myself before I learned – but it looks like you may be reading your Bicron wrong. Based on what I see in your picture measuring the lantern mantles… One can only correctly refer to the CPM (counts per minute) scale if we are not filtering out the alpha/beta activity. mR is only Gamma… so… filter the rest to measure it correctly. You can buy a fancy “official” filter which snaps over your pancake… or you can make your own with 1/8″ (3 mm) thick aluminum sheet metal. It still won’t be super accurate and will vary according to what isotope is being measured – but certainly more accurate than no filter which gives crazy high false readings on the mR scale. We learn that many things are not so spooky after measuring correctly.

    • Administrator June 8, 2015, 2:39 pm

      Again, we are talking about scale here. 100 mR is not a “scary” reading. It is just a baseline to understand what a different type of meter would read. We aren’t trying to compare accurate readings. We’re trying to figure out whether, if you hold this gadget to a tomato, will it show you whether the tomato has absorbed Sr-90 or not. If you buy a bag of flour, was the wheat sprinkled with fallout before it was harvested? Getting lost in technicalities is just a distraction that has only one effect, and that is to make people feel like they can’t understand the science well enough to invest in a tool that could mean their survival.

      • Chris June 10, 2015, 6:52 pm

        This is meant to be helpful so take it the right way… but 100 mR of pure gamma is quite a bit and yes would be “scary” to lots of people if you ever found that in your food or camping gear (hello, thoriated lantern mantles). But you were not measuring Gamma / mR so my point still stands. You are incorrectly referring to the mR scale when you should be referring to the CPM scale for ANY pancake probe measurements. Look closely at your meter and you will see the CPM scale on there too. Always use the correct scale or you will just be misinforming people and leading them astray. Train your brain to think in terms of Counts Per Minute instead of mR when using the pancake probe. There’s a BIG difference between CPM and mR. Get 1/8″ thick sheet of aluminum and see for yourself. For example, on a pancake like yours – (when filtered w/aluminum) it might take around 3600 CPM to equal only 1 mR, (depending on isotope being measured). So, that’s only a three thousand six hundred times difference in dose/reading! 🙂 Common mistake, and not real technical if you think about it. You need to block the alpha and beta to read Gamma/mR. A pancake probe is a great tool to have so you are doing better than most when it comes to contamination sensitivity. You can even get some counts off stuff like granite counter tops and no-salt substitute with that thing.

        • Administrator June 10, 2015, 10:44 pm

          Yes, a beta blocker is actually part of a future I am working on about using a surplus russian pancake probe to be able to tell if there is still alpha and beta fallout coming down. You can do it by adding the shields, both thin aluminum and a second one of paper, to remove the beta and alpha, respectively.

          But… for someone who is just trying to deal with a baseline issue, is there radiation here or not, the point is superfluous. The beta filter is probably why the pancake read higher than the sbm-20s, but the bug doesn’t read any beta at all, and the sbm-20 does read some, though how much would be a crap shoot.

          • Chris June 11, 2015, 1:28 am

            You might be confusing SBM20 (larger) w/SBM21 (tiny). More surface area in the 20 so it’s actually really good for Beta. Yes, the Russian pancakes are a great deal for the price. Most won’t be quite as sensitive to alpha as your American made pancake tube (it’s likely an LND, Inc. tube inside there). The Russian ones have thicker (more durable) mica windows so the tradeoff is less sensitivity to alpha. They are fine for beta+gamma though. So definitely keep the Bicron for more subtle contamination/alpha detecting. Oh and you don’t need to add paper to an aluminum filter. 1/8″ (3 mm) thick aluminum sheet is plenty to block both all alpha and most beta. However if you *just* want to block alpha, you can use a business card thickness of paper. If you feel like adding a third filter to your kit, you can make one special for measuring Strontium 90’s Gamma. It has more vigorous beta which requires more like 5.2 mm thick aluminum to block. You can get close enough with a 1/8″ thick aluminum plus a second slightly thinner sheet just sandwiched together. Chances are you will not need a ’90 filter though. Most stuff wouldn’t be that concentrated in one spot (hopefully!) or we’ve got big problems. I have a few SBM20 tubes here too (note: I’m talking about the 4″ long tubes, not the tiny SBM21 tubes). In general – the 20’s are approximately half as sensitive to beta as your pancake, (just a ballpark and depends on isotope). Smart Geiger likely has a PIN Diode (common/cheap) and only registers Gamma/X-ray. SBM20 and 21 are thin walled GM metal tubes so they let a bunch of beta through. Your pancake probe is not metal windowed, it’s got a *very delicate* mica window. It’s protected under the grill/mesh/screen but easily popped by a dry blade of grass or twig or wire, so be super careful. Even unpressurized flight at high altitudes above 6,000 ft elevation can cause them to flex outward from loss of pressure and rupture. Shouldn’t be an issue as most cargo bays will be pressurized these days. Accidental finger pressure can pop them too, so be careful if you take it apart. As a ballpark idea, our pancake probes are about four times as sensitive to beta as a cdv700’s probe (beta window open), and twice s sensitive as a bare (unshielded) SBM20. Pancake’s real strength is they’re awesome at alpha! Sorry if my points jumped around a bit. Evening caffeine makes my brain wander. That’s enough for now!

          • Administrator June 11, 2015, 9:01 am

            I just ordered some test samples of cs-137, sr-90 and a few other things, so I can bring this down to earth a little more. The idea of the paper and aluminum is to measure with nothing, then add the paper, then add the aluminum. If the meter doesn’t go down, you’ll know that it is all gamma on your meter.

            I have to say, one of my peeves is that people don’t read the material here before commenting, and it is pretty clear in the pics that those are sbm-20 tubes in the red meters. I have never suggested that anyone buy a cdv700 throughout this series.

            Without a gamma spectrometer to get a baseline on the source, it would be very tough to tell what percentage of the sbm-20 reading is beta. I am hoping to learn more and might even buy one. From what I have learned in the last couple days, a gamma spectrometer will be the only real way to measure radiation that has been absorbed into food, or that is dissolved in water.

          • Chris June 12, 2015, 6:07 am

            Well I guess I can’t reply further in the proper place so I’ll stop now. There’s a lot to cover and it is a fascinating topic. And yes, we all have pet peeves. 🙂

          • Administrator June 12, 2015, 10:41 am

            If you saw the amount of idiocy we have to delete here in the comments you would well understand. There is a comment even on this thread about attenuation, as it apparently relates to survival, that the FEMA chart of materials should be ignored because betas are blocked with low z materials. Of course 10″ of cement will block any beta at any fallout rate, so the comment is completely useless.

            In general the field of nuclear science is almost entirely dedicated to science, and not to survival, or to educating people about the real dangers and survival strategies of a nuclear event. Clinton dismantled the CDV program, and the pieces of it are mostly all we have left to defend ourselves.

            People like you who look at radiation as a field of study, but never consider why you are studying it, could do a lot of good. But you clearly didn’t even read the article, which is one of several here that are more substantive than any other prepping or survival website in the world. And we sell none of this stuff, nor do we have any advertisers here for any of it. Our people are teetering on the brink of a complete meltdown of everything, and people like you want to argue about how thick the aluminum has to be to filter out beta properly so that the meters match up. Roentgens and Sieverts are measures of absorbed radiation, and they are universally used, even though different tissues in the body absorb radiation at slightly different levels.

            In Poland after Chernobyl they gave everyone KI and the incidence of thyroid cancers and illness was next to nothing. In Ukraine they forbid the scientists from even testing what was in the air for 3 days, then forbid doctors from diagnosing radiation induced illness for over 3 years. In the US, KI has been regulated as a drug making material. If you try to order it in bulk from photo supply houses you have to fill out a DEA form. So we have to pay $7 for milligrams per person for a substance that is otherwise unregulated and sold in 50lb bags around the world.

            Americans have entitled themselves to be useless, deriving simple pleasure from advertising how much they know in pathetic, self infatuated comments. If you are in a survival discussion, apply what you know to survival. Be useful to your fellow man. The people who read this column have at least taken the first step to learning what threatens them when the support structure goes down, and it is going down. You share what you know about radiation. Another guy shares what he knows about storing food long term. Another girl shares what she knows about keeping bees as pollinators. Maybe we have enough time to have the money to actually do some of this stuff. There is no room for self infatuation in a foxhole.

  • Occams June 8, 2015, 1:52 pm

    Rd Klein has a $5 app that operates on-par with the Inspector Detector, a $600-ish unit.

    The remaining $25 spent here helps fund Skynet’s killer robot program (Terminators), CIA Black Ops, spying, and other unconstitutional efforts.

    Even works with Ubuntu O/S phones, which is what you should be using, anyway.

    • Administrator June 8, 2015, 2:55 pm

      I deleted the first version of this comment because the poster includes things that are irrelevant to a serious discussion about a survival tool, but it turns out that there is something to at least investigate.

      The IOS ap page is here:
      http://www.rdklein.de/html/radioa_ios.html

      The developer appears to have figured out how to use the Iphone/Pad/Pod camera to measure significant amounts of radiation, but it looks like Apple put a wrench in the mix as of IPhone 5. I may return and do an article on this, but if you are on IPhone you may want to check it out yourself.

  • Paul Fi June 8, 2015, 12:39 pm

    Great article and review. I’m not nuclear savvy but it was easy to understand. You were a lot better teacher than some of the professors I had for sure.

  • Eric June 8, 2015, 7:23 am

    EMP + cell phone = dead cell phone = no Geiger detector

    Maybe your cell phone is analog?

    • Administrator June 8, 2015, 7:35 am

      Not actually true. If you read the linked EMP article, you will see that radios, of which your phone is one, are hardened against an EMP naturally, because they have transmitters and receivers in one unit. If they didn’t, the transmitter would blow the receiver.

      • praharin June 8, 2015, 9:52 am

        Are you certain about that? I have my doubts. A cell phone may be a radio, but it is also much more complicated than a simple radio. My research says it “may” be destroyed.

        • Administrator June 8, 2015, 10:02 am

          Current is generated from the antenna which converts a wave into energy. Antennas are tuned to a certain frequency, and the circuit is hardened for that particular frequency, using blocking capacitors. If you bother to read the article that is linked in the article above, you will find that in tests of EMP strength fields, it didn’t even wipe out car electronics. The waves with the most energy are low frequency, which require very big antenna, ie. all those electrical lines. The amount of energy generated by an 800mhz wave at all is questionable, which is what all the tests show.

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