I used to have a quartex from harbor freight and it was very sensitive. I pegged it after getting a Hidascan. The check source on the CDV 700 was pretty good at lighting up the quartex, too. I had a survey meter that Shane calibrated. I don't remember if I got the survey meter to budge, but I did get a sensitive dosimeter to register it after holding it next to my gut for a while. It wasn't the standard 0-200 rem, so it wasn't the 742.

On the meter that is "Overly sensitive;" put the knob to the "Zero" setting, and rotate the knob on the bottom left until the needle points at zero. That might help you out

1:08 you are supposed to zero it out

Buying old Civil Defense survey meters on Ebay IS a crap shoot. But if you're careful, and know what you're looking for, you can pick up a good deal. I buy the CDV-717's, and I make sure they pass both the circuit check, and have no internal corrosion. I'll spend between $35 to $65 on a used meter. Calibration through (radmeters4u) costs $92. But if you buy an already calibrated meter from that site, expect to pay $350-$500! In fact they don't sell meters retail anymore, they use dealers now.

How do you know if your meter is calibrated or not?

The more sensitive the meter the better the measurement. It allows for detection of small amounts of radioactive material in food or in the ground. The cdv700 and 715 are not sensitive enough to detect contamination in food unless it is extremely large amounts of radioactive material. The cdv 700 the one with the detachable probe is your most sensitive unit which is actually useful. The only time you even could use the 715 is if you were near a source that could imminently and severely impact your health. It would not even register at the trinity site or other moderately contaminated aires. It will only register when you are in a location that you really shouldn't be at. The cdv 700 on the other hand will detect much more commonly encountered radioactive sources. If I had to choose one to have with me in the aftermath of a large release from a reactor or other source I would defiantly choose the cdv 700 or preferably something much more sensitive. If your cdv 700 goes over scale or no detect from voltage overflow then you need to leave the airea, simple as that. I would never encourage anyone to get a cdv 715 unless you plan on surviving a nuclear blast and then hiking towards the epicenter.

@tainosavage2169

2 жыл бұрын

Very useful information..Thank you!

I have geiger counters with scintillation probes capable of picking up over 10,000 counts per minute background radiation. Sure my less sensitive counters are great for sitting in my basement and preparing for the nuclear attack… Or scanning my overpriced radioactive antiques… But actually going and finding something? Not a chance. Unless you’re an inch or two away. It’s very important to have something extremely sensitive. Even a plastic scintillation probe (like those sold on eBay by IRAD INC) Will give extremely high sensitivity levels… Approaching 2500 cpm background. For example, let’s say your prospecting for uranium, or trying to find a radioactive source that’s been lost in a metal recycling yard. Or maybe you just want to find some spicy minerals in your own backyard. Or maybe you want to go hunting radioactive antiques… Which are plentiful in all antique stores and junk shops. 10,000 counts per minute background gives me enough data points to easily see the anomalies or spikes. I don’t have to listen to it, I can cut the meter to silent and zero out the analog meter so that it only shows me the spikes above background. Even very expensive Geiger muller detectors only get a few hundred CPM maximum! But At 10,000 counts per minute… A 5% increase is an extra 500 counts per minute! Where a common cheap old geiger counter is around 30 CPM background… With a 5% increase only being 1.5 counts. Good luck finding any anomalies or spikes… And completely forget about it unless you’re only an inch away from the source! I can pick up uranium or radioactive sources from several meters away! These are the same type of detectors that are strapped to helicopters and flown over potential uranium mines… To sense the radioactivity below. I’ve been doing that since the 50s. Really can’t go wrong with a Ludlum model 3 or 12 running a bicron scintillation probe with 2.25“ x 1.5” NAI(TL) Crystal. or at the very least one of the 3 inch DIY scintillation kits from Irad inc. then you can use one of the cheap pocket detectors to pinpoint the source once you’ve located it from several yards away. Other than avoiding nuke fallout, or already confirming radioactive sources that you’ve purchased. Most standard detectors have no use for actually finding and locating radioactive sources. Sure it’s fun to swipe over your collection but there’s tons of radioactive stuff in our every day lives, extremely dangerous government sources lost in scrap yards everywhere… An antique stores full of radioactive goodies. Irad’s DIY 3 inch scintillation probe kits are made of a plastic scintillating material so they aren’t fragile and sensitive like Real crystal. They can be had under $150… And are about 100 times more sensitive than the best Geiger muller tube. But a nal(ti) detector can be had pretty cheap if you look out for them. Do you want something with at least a background of 3000 CPM. They’re extremely fragile and hygroscopic, But you can also identify exactly what isotopes are in the material you find. I’ve seen nice bicron probes go for $100. Good luck to you, and as long as you’re enjoying what you’re doing that’s all that matters. This is just my opinion and my take on the subject. Once you find your first few radioactive source is “in the wild“ it’s pretty addicting.

Link not working. Thanks for the info.

Try ZEROING IT

why would you need one anyway?

@cplinstructor

6 жыл бұрын

James Harty They are very neat collectables and historical artifacts, but they are also useful. The CD V-715 and CD V-717 are both survey meters, they measure high levels of radiation. They are normally useless, but in the event of a nuclear exchange or a nearby reactor meltdown they would be invaluable, they would tell you which areas are safe, or safer anyway. The CD V-717 has the added bonus of a remote sensor that can be up to 25 feet away from the meter, so it can tell you when it is safe to leave your fallout shelter. The CD V-700 is a low range meter, a true geiger counter, it is useful after the initial period after the attack or meltdown when the radiation has fallen below the detectable range of the CD V-715s and CD V-717s. It can also be useful for checking for residual contamination, leaks in your shelter, and contaminated personnel or equipment. It is also a great practice tool for the survey meters and an educational tool to learn about radiation, it’s also FUN, you can just go around measuring random things and discover just how many things around you are radioactive, all while making that ominous clicking sound to scare observers and kids. It is also very useful if you collect depression glass or fiesta wear as it will help you authenticate and locate them. You can also use them for Uranium prospecting.