From what I can tell, nobody is going to send me a Facebook notification 24 hours before Russia, China, “terrorists” (ie. our own shadow government), or the US under official license launches a nuke. Radiation is silent once you are outside the blast radius of a nuclear bomb, so unless news of the blast makes it onto Drudge, how would you even know that a blast has occurred? Up until now we have focused our attention on Geiger tube radiation meters, but I recently found out that those meters tend to BLANK OUT at radiation levels that aren’t even on the level of a CT scan. For this article I consulted with Shane Connor, owner of the famous radiation site KI4U.com. I bought potassium iodide from him and had him calibrate my Civil Defense meter back in the 90s. He is still doing it today, and he calibrated four meters for us for this article.
If you have never seen a Civil Defense meter, they are unattractive yellow boxes that look like they were made in the 1960s, because most of them were. Our nation used to support a strong local Civil Defense force made up of civilians, going back to the early days of the Cold War. After the fall of the Berlin Wall, people became less worried that the Russians were going to nuke us, so funding was gradually cut, then eliminated by President Clinton. Most of the CD meters got put into storage, then eventually auctioned as government surplus. There are still thousands of meters in service today, however, held and maintained by fire departments and other first responders, as well as some smart municipalities. Unless a meter had a battery blow up in it or it was neglected in wet conditions, or was subject to physical trauma, they still work great.
The problem is, most of them are out of calibration. The original FEMA instructions said to recalibrate the meters every 4-6 years when kept in ideal conditions and not jostled about. According to Shane, if a meter hasn’t been calibrated in the last 10 years it for sure needs a functionality test and calibration to assure that it is working even at the most basic level.
Where do you buy a CDV meter? Ebay!… if you don’t want to pay over $300 for one. If you search for “cdv meter” on Ebay, you’ll find tons of meters ranging from about $30 to $150. Unless they meters have been recently calibrated, there is no advantage to the high priced ones. They are just people fishing a price waiting for an “event” to scare people into paying more for them.
The calibration service is another $92. Shane has one of the few machines left that were built for calibrating these meters. There used to be one in every state until Clinton defunded the project. They have calibrated tens of thousands of meters, and many of the municipalities and first responders that still maintain the meters send their meters into KI4U.
According to Shane, there is historically about a 1 in 3 failure rate for meters that were bought out on the open market. My guess is that this number has significantly dropped, because most of the meters you see on Ebay these days are in pristine condition, and some of them even have calibration dates on them.
I bought a total of 7 meters for this article and sent 4 of them to Shane for testing and calibration. Two of the meters I sent had no calibration sticker, and 2 of them did, purchased from this guy on Ebay, who as of this writing appears to only have 4 of them left.
The meters you are looking for are the CDV-715 and CDV-717. The former is the basic model and the latter is the same instrument with a detachable probe on a 15′ cord. I prefer the CDV-717 because you can put the probe outside to detect if there is any fallout that would not reach inside a building. The 717s tend to be a little more pricey though, but the recent lot of them hitting Ebay are in pristine condition and don’t look like they were even handled or taken out of the box. If you are sending your meter to Shane, ship it directly from the Ebay seller to avoid double shipping costs. As long as they know who it is coming from it is no problem. You might be able to snag a $20 savings on your calibration as well, because Shane runs a $70 Ebay ad as a educational door periodically on Ebay.
The CDV-700 is a Geiger counter, not unlike the Geiger counters we already covered here. It is useful for low level radiation, as I’ll explain below, and testing food and water after an event occurs. It doesn’t have the range to guide you out of radiological hot spots if you find yourself in one after a blast. Geiger tube meters blank out after about 100 mR per hour at best. Roentgen, Rad and Rem an be considered equivalents for these purposes, though they have subtle differences as to what they mean and what they measure. More on this below.
I am happy to say that all 4 meters that I sent to Shane passed with flying colors. None of them were off in calibration by more than a few hundredths of a RAD, and this was true for both those with recent calibration stickers and those with no calibration sticker. See the pictures for the actual readings and reports.
We also had them test 4 dosimeter sticks. These are numbered CDV-742 and can be bought in 2 or 4 packs on Ebay for about $30 with an included CDV-750 reset machine. These sticks can’t be fixed or calibrated, but Shane tests them for function under the FEMA guidelines. He gave me a tip, however, that you can check yours for free. Use a dehydrator or other heater to hold them meters at 120 degrees for five days after you zero them with the CDV-750. If they don’t creep up by more than 5% over 5 days, they pass. Shane told me that 93% of the dosimeters that pass this test go on to pass the radiation exposure test. Most that are going to fail at the 120 degree test fail within the first day, or even hours. If you do send in your dosimeters for KI4U to test, make sure to send your CDV-750 as well. Great information on dosimeters and chargers is here on KI4U’s meter website. Beware that the Russian electronic “dosimeters” are not for a high level radiation event.
So now that you have the overall picture of how to buy a CDV meter and how to make sure it works, I will digress a bit into some of the details I have alluded to above. I initially told people to stay away from the CDV meters because it used to be very common to get a bad one, and I thought that the Geiger tube meters were just fine. It turns out that they aren’t. I sent Shane the Radiohobbystore.com kit that I covered in my prior articles and he tested it in his Cesium 137 machine. The meter read great up to 100 mR per hour or 100/1000ths of a Rad per hour, which is the equivalent of 1 mSv, or one thousandth of a Sievert. As I said above, a standard CT scan that most of us have during our lives comes to 10-30 mSv. To give you another rate of scope, 1 mSv/h is the NRC definition of a high radiation area in a nuclear power plant, warranting a chain-link fence. This is not a high level of radiation, so if the meter is going to start blanking out at that point, there is no way to use it for finding and avoiding hot spots during a true nuclear bomb event. It’s scary stuff, but part of being a prepper is facing the truth, and the truth is that you need a real high level meter, and one that has been tested and calibrated.
It is very satisfying to watch the Radiohobbystore.com Geiger counter holding at .10 uSv or thereabouts, but the scary truth is that should a bomb explode without my knowledge, and fallout begins to irradiate me, the probably behavior for the meter is that it simply conks out, or it appears to. Shane said that this was actually a pretty good circuit because when removed from the radiation field the meter did come back on and worked as expected, but that it did indeed go dark just over 1 mSv per hour. Who’d a thunk it right?
How much radiation is not recoverable? According to the 1983 FEMA book, Safety In Shelters, under 50 Rads of exposure doesn’t have any real lasting repercussions. The biggest danger is in the two weeks after an explosion, because the prevailing winds can carry nuclear fallout for miles, even hundreds of miles. Fallout is primarily made of alpha and beta particles, including Iodine 131, which is the biggest killer in humans. If you stay inside during these two weeks your exposure to alpha and beta will be minimal, because these particles are fairly heavy and fall straight down once they are released from the upper atmosphere. If you take potassium iodide (KI), as I’ve explained in a prior article, you will be much less subject to the effects of fallout as well. The fallout also does irradiate gamma, and that is primarily what your CDV meter will tell you. If you are in a 1 R/h field, you can monitor that for a day to see if it is going down. Staying put or moving will be a function of practicality and risk, so good luck regardless. After the fallout has reached its half life, within about 8 days of the blast, the danger of breathing or eating radiation starts to go down, but keep taking your KI for two weeks. Gamma from fallout also decreases, and your meter will tell you that. If you are close to the blast you’ll have to get out of there regardless, because the gamma will be very high for some time. The same goes for nuke plant explosions and leakage. Under 200 rads seems to be recoverable, just as a rule of thumb.
Shane also offers for free a copy of the book, Nuclear War Survival Skills in PDF format. He has been on the cutting edge of helping people understand and survive nuclear war for decades, and you really should just get a meter, send it in, and be grateful that you did it in time. If you did it a decade ago like I did, believe me, you won’t be sorry later that you “wasted your money.” The war in Ukraine is going hot again. We have a new CIA created boogeyman in ISIS, and the world is an much more unstable place than it was ten years ago. Ten years from now we still may be awaiting “the big one,” and lets hope we don’t see it in our days. There is a megaton of free information at KI4U.com and RadMeters4U.com, as well as a list of retailers for Shane’s more expensive radiation protection products. Just beware that much of the site was created when the web was young, and some of the text is center justified and hard to read, but it is all good information, and 100% relevant to what we all see when we wake up and look around today. There is no better source of information about what might happen in a nuclear war on the web that I have find, and it is worth your time to do the research and prepare for it today.
These are the four meters and their results on calibration. Click for a larger picture they are each 2,000 pixels wide so they can be read.