KNOW YOUR CIVIL DEFENSE METERS
May. 13th, 2008 09:47 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
funraniumAs a public service, because eBay and Craigslist managed to annoy me so the other day, I have a selection of Civil Defense radiation detectors for your pleasure. Let us begin with the Victoreen Model CDV-715 ion chamber:
The 715 is a solid metal body construction milspec case surrounding a pressurized ion chamber with a 4 decade range. If you zoom, you'd notice that the sensitivity of the meter face is in R/hr. This little unit is something I like to think was designed to keep the hands of frightened Army privates busy while they die from radiation exposure in the event of a nuclear war.
Because it is a sealed metal case, the only thing that this ion chamber can see is gamma radiation. In terms of damage to human tissue, 1R of gamma exposure is equal to a dose of 1 rem. The annual permitted occupational radiation dose for trained radiation workers is 5 rem. The first noticeable acute radiation sickness effects start at 25 rem, with the 50/60 dose (50% dead in 60 days) at 300 rem.
If you have a gamma dose this meter can see...in R per hour...you are already in a world of trouble. The gamma dose you're seeing is actually more likely to be brehmstrallung from the interaction of beta particles with the hard metal case of the meter. Which means your actual dose is much higher and the meter you really need is the Victoreen Model CDV-720:
The 720 is remarkably similar to the 715, but instead of having a pressurized ion chamber, it is open to atmosphere with a thin window that can be covered by a sliding metal shield. In this way, the 720 can be used to measure beta doses, something there is likely to be an awful lot of in the event of fallout. I like to think this is a meter that was meant to be given to the sarge to determine whether it was safe to go outside the bunker yet. It still has a "you're gonna die" meter face but it is a much more informative death meter than the 715.
For the specialist, you would give them the V-700 GM detector (with optional "hot dog" or "pancake" probes, hot dog shown in picture):
Once you had determined it was safe to go outside, with the suitable expenditure of privates weilding 715s, the specialist could be brought forth with the 700 to look for specific locations of contamination, radioactive hot spots if you will. You know, to survey the post-nuclear holocaust survivors you might find and determine which ones are clean breeding stock. Important things like that.
Let us review:
CDV 715 - Gomer Pyle walking around in the mushroom cloud is almost as good a direct reading instrument as this meter.
CDV 720 - Good enough for the people of Jericho to figure out when it was safe to come out of the bomb shelters.
V 700 - The 1950's meter of choice you want when you go strolling away from Vault 13.
Yes, I am eagerly waiting for Fallout 3 in October. Don't judge me.
The 715 is a solid metal body construction milspec case surrounding a pressurized ion chamber with a 4 decade range. If you zoom, you'd notice that the sensitivity of the meter face is in R/hr. This little unit is something I like to think was designed to keep the hands of frightened Army privates busy while they die from radiation exposure in the event of a nuclear war.
Because it is a sealed metal case, the only thing that this ion chamber can see is gamma radiation. In terms of damage to human tissue, 1R of gamma exposure is equal to a dose of 1 rem. The annual permitted occupational radiation dose for trained radiation workers is 5 rem. The first noticeable acute radiation sickness effects start at 25 rem, with the 50/60 dose (50% dead in 60 days) at 300 rem.
If you have a gamma dose this meter can see...in R per hour...you are already in a world of trouble. The gamma dose you're seeing is actually more likely to be brehmstrallung from the interaction of beta particles with the hard metal case of the meter. Which means your actual dose is much higher and the meter you really need is the Victoreen Model CDV-720:
The 720 is remarkably similar to the 715, but instead of having a pressurized ion chamber, it is open to atmosphere with a thin window that can be covered by a sliding metal shield. In this way, the 720 can be used to measure beta doses, something there is likely to be an awful lot of in the event of fallout. I like to think this is a meter that was meant to be given to the sarge to determine whether it was safe to go outside the bunker yet. It still has a "you're gonna die" meter face but it is a much more informative death meter than the 715.
For the specialist, you would give them the V-700 GM detector (with optional "hot dog" or "pancake" probes, hot dog shown in picture):
Once you had determined it was safe to go outside, with the suitable expenditure of privates weilding 715s, the specialist could be brought forth with the 700 to look for specific locations of contamination, radioactive hot spots if you will. You know, to survey the post-nuclear holocaust survivors you might find and determine which ones are clean breeding stock. Important things like that.
Let us review:
CDV 715 - Gomer Pyle walking around in the mushroom cloud is almost as good a direct reading instrument as this meter.
CDV 720 - Good enough for the people of Jericho to figure out when it was safe to come out of the bomb shelters.
V 700 - The 1950's meter of choice you want when you go strolling away from Vault 13.
Yes, I am eagerly waiting for Fallout 3 in October. Don't judge me.
