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Do you really want a Geiger counter?

By Craig Douglas
October 16, 2013

Do you really want a Geiger counter? by Craig Douglas (Oct. 16, 2013)

A strange thing happens in front of my eyes every weekend at the shows I do.  An individual comes to me in a panicked state that has fears of Japan radiation in the air, water or food coming to their doorstep.  Fear not, if you study the physics of how radiation travels, you will find your fears unfounded, unless you live near the site of the accident.  I have to talk them out of buying a Geiger counter and they are frankly quite confused over that.  Here’s the basics of what is available to purchase dealing with radiation detection with associated advantages and disadvantages.

Radiological Survey Meters  (old Civil Defense models CD V-710, CD-V715 and CD-V717):  Most immediately call these Geiger counters because of the TV/movies, but they are not.  The detectors in these are ion-chamber devices for high level radiation, usually just gamma and X-rays, which are the most deadly in the short term.  Usually these are only good for levels of around 1 R (roentgen) or higher.  These measure levels that could quickly make you sick or kill you if you didn’t have a shelter.  All the emergency services were once equipped with this sort of equipment in the form of the old Civil Defense equipment which is still widely available for under $100.  New modern units will start at over $1000.  With these units you can’t measure contamination in food or water, radiation in items around your home, background radiation, or any low levels whatsoever.   In fact there is no radiological source you can legally own to make the unit respond at all.  Your best bet to test one of these is to expose these to an X-ray machine if you can get access to one, or have it professionally calibrated (many models have an internal circuit self-check function, but not a radiation source).  These units are the right choice if there is a nuclear detonation or power plant accident – near your location that is.  Don’t expect any modern digital equipment to function after there is an Electro-Magnetic Pulse (EMP), as in say a nuclear detonation.  This applies to all the units described in this article.  Some may be “EMP hardened”, but there is a lot of controversy about these actually withstanding “the big one”.

Geiger Counters  (Such as the old Civil Defense model CD-V700): This is what everyone seems to be searching for when seeking a radiation detection unit, but are you sure you know what it is and what it does?  These are generally 10,000 times more sensitive than the ion chamber devices described above, usually measuring around .1 mR to 50 mR (milliroentgen) of beta, gamma and X-rays (although with a special probe some can also measure alpha).  These are levels that are not dangerous when exposed to short to moderate durations, such as when traveling in an airplane. 

With a Geiger counter you can measure things around the house, but you will be quite disappointed to find none with your new toy (many have a radioactive source on the side for testing function of the unit).  Unless you scour the antique stores for old thoriated lantern mantles, Fiestaware, radium clocks and watches, or vaseline glass, you are likely to find nothing.  Usually the purchase of a Geiger counter encourages one to find SOMETHING radioactive to buy as to justify the purchase they made thinking they were going to find some “trouble” from Japan.  As I have said for years, if you are buying a Geiger counter because of fears of Japan, you are wasting your money. 

So what about food?  Unless the levels are very high (this is possible if it was grown in Japan), you will not find any radiation in food with a Geiger counter.  As shown on the radiation page of my website, the naturally radioactive food items of bananas and brazil nuts cannot be measured with a Geiger counter since they are naturally right about at normal background radiation levels.  Contaminated food will be at levels much lower than normal background radiation levels, and you can’t measure anything lower than background radiation with a Geiger counter
Also when there is a true emergency, the detector in the unit, called a Geiger-muller tube, will easily saturate (overload) and your un it will be completely dead!  The needle won’t peg right, there will be no Geiger tick noises…  just the appearances of no radiation.  That’s why the emergency services would never rely solely on a Geiger counter because it would show zero on the meter in a high level event. 

Although a Geiger counter can measure background radiation levels, you really can’t measure accurate background levels with one because of the random nature of ion particles.  With more sophisticated computer based digital Geiger counters you can obtain averages, data logging and more, even of normal background radiation.  Expect used units to be in the $100 to $200 range, new units will be generally from around $500 to $2000.

Mass Spectrometers:  This is what you will need if you think you are being poisoned from Japan, and your only hope of finding any contamination in food.  It will detect the tiny trace amounts, isolating each radio isotope individually (such as caesium 134 and caesium 137).  You place a sample into the unit which then converts the sample into gaseous phase ions.  Mass spectrometers are operated in a vacuum to avoid collision of the ions with other molecules.  A computer controls the instrument, acquires and manipulates data, and compares spectra to reference libraries.  These are not portable; they are generally used in lab settings.  I’m sorry I don’t have personal experience with mass spectrometers as it’s quite outside of my league to afford just to satisfy people who don’t believe in basic science of how radiation travels.  Expect used working mass spectrometers to start at around $5000.  I don’t really think you are prepared to hear how much they cost new…  starting at about $100,000!

Conclusion:  If you want to check for some sort of radiological contamination from Japan, you need a mass spectrometer.  Some higher end Geiger counters can read averaged background readings but are otherwise toys.  Radiological survey meters are only for real emergencies with dangerous levels of gamma radiation.

Craig Douglas         


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All information posted on this web site is the opinion of the author and is provided for educational purposes only. It is not to be construed as medical advice. Only a licensed medical doctor can legally offer medical advice in the United States. Consult the healer of your choice for medical care and advice.