The LinuxSlate.com Guide to Buying a Personal Radiation Detector is published here with some trimming and updates. Any Broken Links will be fixed as content is moved from LinuxSlate.com to here.
Since the accidents at the Chernobyl Nuclear Power Station in Northern Ukraine, and Fukushima, Japan radiation continues to be a very real part of daily life for people in the places affected by these tragedies. One tiny piece of good news for these folks is that modern technology has made radiation detection devices more compact, reliable, affordable, and easier to use over the last several years. Consumer-friendly radiation detectors are now available to help people avoid contaminated products and places. A few enterprising people have realized that there is a small but lucrative market for reselling these devices to the rest of the world. This makes a variety of devices available that were simply unknown to westerners a few years ago. If there is a market for these devices in the west, then logically there is a need for a Buyers’ Guide. This guide is intended to explain these devices to western consumers, to let them know what features are available, and to help them avoid paying too much.
Does Joe Consumer Really Need a Personal Radiation Detector?
Obviously, I think one of these inexpensive devices is a good thing to own. Without being too wordy, I will try to summarize some reasons below:
- Natural “Hot Spots” — These exist virtually everyplace in the world. They are caused by natural Uranium deposits, Radon gas, etc. (US Radon map at EPA.gov). Did you know that we have even discovered naturally occurring nuclear reactors right here on Earth? (Natural nuclear fission reactor – Wikipedia.org). Knowing the natural radiation signature of your environment is a good thing.
- Common Household Items that are Made from Radioactive Materials — Spark plugs, lantern mantles, certain cups and plates, watches, smoke detectors, and other common items have in the past been made with radio active materials. Some still are. I would bet that most households contain something at least mildly radioactive. Review commentary on the Linuxslate.com Forums tells of radioactive items that I found with each of the Radiation Detectors I have reviewed.
- Household Items that Somehow Have Become Radioactive — Even if a product is not made with radioactive materials, it may be possible for it to become radioactive. Think about the items you bought last time you went to the store – do you know everything that was in the same shipping container with those products? Did that set of food storage containers come with a sheet describing radiation levels in the warehouse it was stored in? You may even be exposed to radioactive people! This happened to me – you can read about it in my review of the EcoTest MKS-05. For now, this review remains on Linuxslate.com.
- Radioactive Food — Due to the nuclear accidents, natural radiation, or improper storage or shipping, some food may become radioactive. While tests are done to insure that our food is safe, and that radioactive food is destroyed, it may still be possible for some to make it to our plates. If, for example, farmers or shippers are not compensated for food that should be destroyed due to unsafe levels of radioactivity, there could be a temptation to pass it on to the market. Food is also regularly irradiated to kill parasites and bacteria. This is a good thing, and does make our food safer. If you die of bacterial food poisoning, then you need not worry about radiation. I just hope they set the timer correctly when they irradiate my food, and that nobody gets confused and gives it a few extra trips through the irradiation chamber.
- Government Response to Disasters and Accidents — It does not take a nuclear accident to make us aware of the fact that the government sometimes does not react as efficiently as we would like. Consider the response to the disaster caused by Hurricane Katrina. It is best to be independently prepared. The local “cop on the beat” probably does not have a degree in nuclear physics, and may not be prepared for even small releases of nuclear materials.
- The Threat of Nuclear Terror or Acts of War — Terror attacks, by definition, thrive on fear and panic. Terrorism experts agree that the panic caused by a “Dirty Bomb” would likely injure or kill more people than either the initial explosion, or any resulting disease. A radiation meter toting public would be much less likely to panic, and would be able to make informed decisions about what action, if any, they would need to take. By removing the panic, the effectiveness of such an attack, and thus the incentive to carry it out, is significantly reduced.
- Conversation Piece — I don’t live inside a mountain. I don’t have a 10 year supply of MRE’s, and I don’t have a lead-lined room in my house. If you read the rest of this site, however, you will see that I do like cool technology. The radiation detectors mentioned here are not expensive, and are definitely cool electronic gadgets. Unless you travel with a particularly dim crowd, I can virtually guarantee hours of conversation about energy, physics, world politics, or the environment after your pull out your “rad” meter.
Radiation Basics:
Manufactures or resellers of radiation detectors often have some information about radiation. Another good place to read up on the subject is on Wikipedia. However, I will provide a quick background here.
Ionizing radiation (Also referred to as Nuclear Radiation) is what we are talking about when we say that something is “Radioactive”. Ionizing radiation gets its name from the fact that it can knock sub-atomic particles out of an atom, thus altering or destroying that atom. This is what makes ionizing radiation so dangerous.
RF radiation, such as from mobile phones, commercial antennas, microwave ovens, and wireless data links does not destroy atoms. (although it can raise their energy levels temporarily). Your mobile phone, wireless PDA, or microwave oven is not radioactive, nor can it make you, or anything else radioactive.
The detectors and meters that are the topic of this guide detect the more dangerous ionizing radiation only.
OK, so now that we have RF radiation and ionizing radiation separate in our minds, lets talk about 3 important types (sources) of ionizing radiation:
- Alpha Particles – Alpha particles are the cores (nucleus) of helium atoms (helium balloons contain complete helium atoms, and are not radioactive). Alpha particles are easily stopped as soon as they hit anything (molecules of air, or a sheet of paper). Even though they are easily stopped, they can damage the atoms of what ever they strike. If you swallow a source of Alpha particles, they will be stopped by your insides, and damage will occur. We really do not want to eat anything that is emitting Alpha particles.
- Beta Particles – Beta particles are also pieces of atoms flying along without the rest of the atom. In this case, it is an electron and it is traveling free (not down a wire, for example). It takes a little more to stop a beta particle, but thin metal – even tinfoil will stop most of them. Again, if you swallow a Beta source – what stops them (and what is damaged) is going to be your insides.
- Gamma Radiation – Gamma rays are made of the same particles as non-ionizing radiation, but at much, much higher energies. Gamma Rays, Cosmic Rays, and X-Rays are all basically the same thing. The only difference in the terminology stems from how the particles are made:
- Cosmic Rays are natural, and come from space. Stars (including our own Sun), Black Holes, etc. all make Cosmic Rays. We live in a constant drizzle of natural Cosmic Rays.
- Gamma Rays come from the decay of radioactive elements here on Earth. This can be natural, or from man-made nuclear reactions.
- X-Rays are created by man-made devices, such as medical equipment, or basically anything in which electrons strike metal. (Such as picture tubes).
Gamma Rays are very hard to stop, and a Gamma source even quite distant from the body can be very dangerous.
There are other particles not listed above, but Alpha, Beta, and Gamma are the 3 most common forms of ionizing radiation.
Detecting Radiation:
If any of the ionizing particles mentioned above pass through a tube of a certain (harmless) gas that has an electrical charge, a detectable electrical pulse will be generated. This is called a Geiger-Muller tube, after its inventors. In the rest of this article, I will refer to it as a GM tube. The electrical pulses generated by the GM tube are counted by either analog or digital circuitry. If the counts are fed into a simple computer chip, they can be averaged over time and converted into different measurement units. The device can also trigger alarms to warn of dangerous levels. The combination of a Geiger-Muller tube and counting circuitry is where we get the term Geiger Counter. The term Geiger Counter has become somewhat outdated, but all of the devices that are the subject of this article contain GM tubes. This article does not cover scintillation devices or any kind of dosimeter without a GM tube. For more details on the difference between GM counters and other types of dosimeters, see This Article on RadMeters4u.com.
Do Radiation Meters give off Radiation? Am I Going to Get Cancer from Having one of These Devices Around?
No. These devices detect radiation, they do not cause it. Thinking you are going to get radiation from something that detects radiation is like thinking you are going to get fat from standing on a scale. Even surplus radiation meters were likely never used in a radioactive environment. If they were, they would not be available for sale. GM tubes do operate at high voltage, and thus these devices may create a very small electrical field around them. This field is much weaker than emissions from many other common devices such as TV’s, computers, microwave ovens, mobile phones, etc. In this sense, using a radiation meter is comparable to using a pocket calculator
Features to Look for:
As I mentioned, radiation detectors simply generate an electrical pulse when an ionizing particle passes through the detector tube. Some simply flash a light and make a click for each pulse. Others pass the pulse to rather sophisticated computing circuits and digital displays. Extra features are always nice, but a simple flash is fully sufficient to indicate the presence of radioactivity. My DRSB-88 has only a light and clicker (See Review Here), but if I place it near something, and it starts to flash frequently, I know that object could be dangerous.
Units with digital readouts simply convert clicks over time to common units of radiation. Having them do this automatically is a very nice feature, but you pay for it. In addition to the flash and click, some of the low end units have another light and possibly a buzzer that warns of levels above a preset warning level.
A very important feature is some sort of window or removable cover over the actual detector. As I mentioned, alpha particles are stopped by almost anything. If the detector is inside a metal or plastic device, it is not going to detect alpha particles. To solve this problem, better units have a removable cover or window that when opened, exposes the GM detector. When transporting the device, or specifically to filter alpha particles, the cover is closed or replaced. Obviously, a window is better than a simple cover, since covers are likely to be lost. If the cover is lost, the detector becomes very susceptible to damage.
Some detectors claim to be able to indicate the direction to the source of radiation. It would take thick concrete or lead shields to block gamma rays coming from different directions, so unless you need a crane to lift the device, it cannot provide any meaningful directional information about a gamma source.Claims of ability to indicate direction would make me suspicious of all claims made by that manufacture or vendor.
Almost all personal radiation meters are powered by batteries. I prefer radiation meters that use common types of batteries. In an emergency, it may be difficult to get specialized batteries. I would avoid rechargeable batteries. Rechargeable batteries loose their charge over time, and it is possible that the power will be out, or that you will not have time to charge them in an emergency. Modern, name-brand alkaline batteries have a very good shelf life, and are better than they used to be about leaking. If stored in, (or better yet — in a bag next to) your radiation meter, you can count on them working even after a number of years.
Sensitivity and Accuracy:
With modern crystal controlled timing, even very inexpensive units are generally fairly accurate. On the other hand, the size of the GM tube its self is an important factor for some applications. The GM tube in pocket or keychain detectors is usually very small. Because of this, fewer ionizing particles are going to pass through it than would pass though a larger tube. Think of the particles as drops of rain — a bigger bucket is going to catch more rain than a small one. This does not mean that small units are not going to give the correct reading. The difference in detector size becomes important when scanning a room for a suspected radioactive object. A unit with a small GM tube may have to be very close to the object or have a significant delay before you notice it react.
Construction and Circuit Design:
Consumers in western countries have basically 3 choices. The first is buying expensive laboratory grade devices. The second is buying surplus civil defense meters. The third option is purchasing devices made for retail sale in Eastern Europe. If you are in a position to afford lab equipment, and you can find one that is compact, battery powered, and easy to use, then that is your best option. Antique civil defense units are best purchased for their nostalgic value primarily, and utility second. Even if a surplus meter has been recently calibrated, the components may be so old that the calibration may be invalid a weak after it is done. If you walk into your local grocery store with a big yellow civil defense meter, it is very likely that you will get more attention than you really want.
The last option is best for most people who want a reasonably sized, and consumer-friendly device. Today, there are a wide variety of personal radiation detectors available from China, Russian and Eastern European companies. It is important to understand that these companies are not big, established consumer electronics manufactures. Do not expect the industrial design or construction to be like that of a contemporary mobile phone. In many cases the build quality is more like hobby projects I made in high school. The circuitry in some of the sub- $20 units is more reminiscent of a 1970’s transistor radio. This isn’t necessarily a problem, however. Many 1970’s transistor radios still work. Some Russian circuit designs may appear strange by western standards, but they function well. The more elaborate devices with LCD displays contain logic and microprocessor chips made by the established chip companies. The use of digital technology insures that these meters will not “drift” or need re-calibration.
Cost:
Let the buyer beware: Some Radiation Detectors are being sold for outrageous prices on eBay and specialty sites. On the street in places like Russia and Ukraine simple detectors are sold for a few dollars. From my research, the prices on eBay or websites reselling to the US and Western Europe are about twice what the devices sell for on the street in Russia, Ukraine, etc. Given the effort these resellers go through to market the devices in English, translate specifications and instructions, and deal with international funds transfers, I feel that this markup is completely fair. Beware however, of prices much higher than this. I have seen keychain detectors selling for $149.99 on eBay!
Disclaimer:
THIS DOCUMENT IS PROVIDED BY THE AUTHOR “AS IS”. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES, INJURY, OR ILLNESS ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENT, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE, INJURY, OR ILLNESS.
IF YOU HAVE SOMETHING THAT YOU THINK IS RADIOACTIVE, OR OTHERWISE HAZARDOUS, OR IF YOU SUSPECT OTHERS OF HAVING SUCH, CONTACT YOUR LOCAL POLICE. THIS GUIDE IS A TECHNICAL DESCRIPTION OF CONSUMER ELECTRONIC DEVICES ONLY, IT DOES NOT, NOR DOES IT PURPORT TO GIVE MEDICAL OR ANY FORM OF HEALTH ADVICE. IF YOU SUSPECT THAT YOU HAVE BEEN EXPOSED TO A HAZARDOUS SUBSTANCE, OR ARE HAVING HEALTH PROBLEMS, CONTACT A PHYSICIAN OR YOUR LOCAL EMERGENCY SERVICES.