The guide to
Buying a Personal
Radiation Detector

NEW: You can discuss this on the Forums

Note: (15 March 2011) This article was originally written over 5 years ago.

In light of the Earthquake/Tsunami in Japan, and the catastrophes at the Fukushima Daiichi Nuclear Power Station, it is currently getting a lot of traffic. I am monitoring the situation closely, and I will make comments if/as I deem appropriate on the Forums.

Please note that in the 5 years since this article was posted, and especially in light of the current situation in Japan, the prices for radiation meters has climbed significantly. Prices mentioned in this article are for normal, non-emergency times, and even then would have to be approximately doubled for just the current economic situation.

I am very happy that I purchased my MKS-05 when I did (That's the “Pre” part of preparedness). I can report that it still works, and remarkably, it is only on it's second set of batteries!

If you are with the press, and would like information on these devices, or to arrange a live demonstration, please email me at the graphic email address on the bottom of the Home Page, or PM Administrator on the Forums.

I would also like to mention that I have great sympathy and hope for the Japanese people as I used to live near Tokyo.

Lastly, If you have one of the Personal Radiation Detectors mentioned here, or a similar device, and you are in an area that is or could possibly be affected, please post your device type/model, normal readings, and any changes on the Forums. Thank You.

The Guide to Buying a Personal Radiation Detector
20 years after the accident at the Chernobyl nuclear power station in northern Ukraine, radiation continues to be a very real part of daily life for people in the places affected by this tragedy. 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. Right now, this market is mostly being serviced via eBay sellers. The number of eBay sellers of Russian and Ukrainian radiation detectors and meters has tripled in just the last few months. 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 buyer's 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.

Please Read Disclaimer Below.

Click Here to Jump to the Links Section, Where you will find Links to Reviews of Specific Radiation Detectors.

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:
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 (Link Below).  However, I will provide a quick background here.
Ionizing 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.
          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 Gieger-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 Gieger-Muller tube and counting circuitry is where we get the term Gieger 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 the Link Below.

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, and even if they were, the odds that they "picked up" any significant amount of radiation is extremely unlikely.  If they did, they would not be available for sale.  Some very old civil defense or survey meters do have a very weak radioactive test sample attached to them.  I definitely would not recommend eating this sample, or placing it under your pillow, but short of literally doing something like that, the test source is harmless.  Most meters do not have any such test source and emit no ionizing radiation.  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, or using a PDA that does not have wireless capability.

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, but if I place it near something, and it starts to flash frequently, I know that object is dangerous.  In this case, displaying a radiation level on a meter or digital display is meaningless in a way, since I would get a totally different number by moving the detector a few inches closer or farther way. Once you get used to how often your detector clicks when detecting normal background radiation, you will notice any significant change.  For example, if you are if you are considering buying a house, take your detector with you. Even without a display, you will be able to notice if the detector flashes more or less often than it does at your present home. With the help of a watch, events per minute can be counted even on units with no display or meter. By factoring in some other known quantities, counts per minute (CPM) can then be converted to other units. Basically, this is what the units with digital readouts do, and having them do it 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. While this alarm feature may make you feel more comfortable, the limits are often not adjustable.  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. Other sources are usually not detected unless you are fairly close to them anyway, so by taking a few steps in different directions, any detector or meter will help you locate the radioactive object.  Claims of some special 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:
Accuracy, per sey, is not an issue for devices that have only a light and a clicker.  Units that count dose, (i.e. ones that have a digital display), must contain a timer.  With modern crystal controlled timing, even very inexpensive units are sufficiently 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 (that have a display) are not going to give the correct reading.  When converting counts to RADs or Sieverts, the counter should factor in the detector size.  Again, with modern electronics, even the inexpensive ones can do this calculation correctly.  Consider the following example:  If I were to go someplace where the ambient radiation level is 10 times what it was elsewhere, both a unit with a large detector, and a unit with a small detector should indicate 10 times higher counts per unit time than they did before.  Also, if I am testing a particular object for radioactivity, I will likely be placing the detector very close to, or directly on the object in question. Even the cheapest detectors make it very obvious when they are in close proximity to something even mildly radio active.  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 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 via an on-line retailer or auction house.  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.  For most of us, this means purchasing them from eBay, or some on-line reseller.  It is very unlikely that it will be possible for the consumer to see or try the devices prior to purchase.  This guide does not cover the intricacies or potential dangers of buying on eBay or buying from unknown on-line retailers.  I will caution, however, that expensive electronic devices are favorites for those committing fraud on on-line auction sites.  Learn to be a savvy eBay'er or on-line shopper.
That said, there are a wide variety of personal radiation detectors available from Russian and Eastern European companies.   It is important to understand that these companies are not big, established consumer electronics manufactures line Apple or Sony.  Do not expect the industrial design or construction to be like that of an iPod or Playstation Portable .  In many cases the build quality is more like hobby projects I made in highschool.  The simple units with black or white cases and nearly square corners are the worst in this respect.  They are made of a brittle substance that either is Bakelite, or some plastic that is very similar to it.  Expect battery doors,  catches, clips and covers to break easily, or simply fall off after some use.  Units that look like a more modern design are usually more up to expectations for consumer electronics. 
The story is similar for the insides of these devices too. The circuitry in some of the sub- $20 units is reminiscent of a 1970's transistor radio. This isn't necessarily a problem, however. Many 1970's transistor radios still work. Also, some Russian circuits designs may appear strange by western standards, but they function well.  Even the cheapest units that I have personally reviewed seem to get very good battery life. Although these units do not use the latest construction techniques, they also seem to be at least relatively durable. In my review of the DRSB-88, I mention that I accidentally dropped it onto a tile floor twice, and it is still working. It is very important that these units never be disassembled. Due to the afore mentioned construction techniques it is very likely that if you take one apart, you will never get it back together and working. Additionally, the GM tubes run at a very high voltage. Even a keychain device that runs on a couple watch batteries has hundreds or thousands of volts inside. If opened, they can cause a serious electric shock even if they are switched off and/or the batteries are removed.  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 recalibration.  Speaking of calibration, some units come with a certification from one or more countries.  These certificates have no legal backing outside the country of issue, and there is no guarantee that a certain vendor is even providing an authentic certificate.  However, If you can find the manufacturer's website (not just the retailer's), and they mention the certificate, then at least you know that the particular unit has been approved as genuine and accurate by the respective governments.


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!   An educated guess (backed by a review below that mentions them selling in the US for $8) is that they sell for $5 to $15 dollars in retail stores in Moscow or Kiev.  Thus, an auction starting price of $29.99 is in my opinion fair (I could not find anyplace to buy them for $8), but I would attempt to avoid higher "Buy It Now" prices, and the $129 to $149 prices are, in my opinion, not good deals.  A good rule of thumb is that no radiation detector without a digital display is worth more than $50.   Obviously, there are exceptions to this rule.  A rare classic Civil Defense or lab meter in premium condition could have significant value as a collectors item.  Also, make allowances for other things included with the meter, such as batteries, chargers, additional books or videos, etc.  Good quality, modern, digital counters with programmable alarms and other features are available in Eastern European countries and Russia for under $80.   Again, you will pay for the service of someone distributing them, so allow for that, but if you pay over $200 for one, it had better be a calibrated piece of lab equipment.
Lastly, note that many sellers in Russia or Eastern Europe use third party "money handlers" to handle auction payments.  The seller will instruct you to send payment (PayPal, Credit Card, Money Order, etc.) to a third party in the US.  The third party will acknowledge payment to the seller, and the seller will then ship the product.  The third party will then transfer payment to the seller (less a profit, of course).  This should set off every warning bell in your head about buying on-line or on eBay.  I do not recommend these types of transactions for first time eBayer's.  Check out these sellers and their payment partners before bidding.  If you do not know how to check out the seller and the payment method carefully, then get some help from someone who does, or simply avoid the auction.  It is beyond the scope of this document to teach you how to do these checks, or what to look for.  I can say however, that while there is a lot of on-line fraud, and some of it is based in Russia, there are also legitimate sellers and payment agents that do transactions like this on a daily basis.  Another thing that I think is kinda cool about these gadgets is simply looking at the postmarks on the package when it finally arrives.  Most of us do not receive mail from Russia or Ukraine on a regular basis.

In Closing, I want to make something clear.  I am NOT  against nuclear power.  In my opinion, spent nuclear fuel in a fuel rod is easier to control (or recycle) than the products of burned coal or tar in the atmosphere. Obviously, neither coal, oil or nuclear fission power is the ideal solution. I have been following the efforts over at the National Ignition Facility (Link Below).  Anybody from there want to to see a copy of my resume?
Please post on the forums if you can provide a review or a link to a review of any such device.  I particularly need reviews of the "DRSB-90", and the "MASTER-1".  Please Post comments, questions, reviews, or stories of radioactive things you have found to the Linuxslate Forums
submit to reddit

General Info about Radiation
US Radon Gas Map
Wikipedia Entry on Natural Nuclear Reactors
Wikipedia Entry on Ionizing Radiation
What's the Difference Between Survey Meters, Geiger Counters and Dosimeters?
Radioactive Products and Other Sources Of Radiation
National Ignition Facility (Lawrence Livermore National Labs)

Reviews of Specific Personal Radiation Detection Devices:
New: review of the IdealRatio Rodnik 3 Portable Radiation Detector
    Review: PerfectRatio Rodnik 3 review of the DRSB-88 review of the Ecotest МКS-05 "Terra-P"
Review of a keychain detector at
Dr. Covington's WeBLOG  (Review of the DRSB-01)
Steven Young's Review of the DRSB-01  (Another excellent review of the DRSB-01  - With a cool video.)


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