I am in the process of trying to set up a reliable dosimeter charger
system for a relative. The type of dosimeter I'm speaking of are the
pen looking devices that are zeroed after exposure to radiation so that
they can be reused over and over agin. There are a couple of types of "chargers" used for this process:
https://pim-resources.coleparmer.com/item/l/radiation-alert-the-charger-radiation-dosimeter-charger-8192200.jpg
https://i.ebayimg.com/images/g/9X0AAOSwcm5fNxcf/s-l1600.jpg
I personally own the first type above (the coleparmer unit). It doesn't
need power, and uses a piezoelectric element that is pressured to
produce charging, then can be bled off until the dosimeter is zeroed. However, I got mine in a trade deal with a bunch of other equipment, so
it was essentially free. What I like most about it is that it doesn't
need any kind of power source for charging dosimeters unlike the second yellow one above that needs a 1.5V battery.
It is the type I own that I had hope to obtain for a relative too, but
at the prices I see them go for, it is out of the question! So, that
leaves the yellow ones that use a 1.5V battery. I do happen to own a
couple of those, but find them much harder to use than the trigger
charger. I was considering modifying it so that it wouldn't have to use
a 1.5V battery. Only a bendix 643 (CDV 750 model 1) used a pump charger
that must have been similar to the trigger charger I use, but I have yet
to see one in the used marker. How would you go about modifying an
existing charger so no battery would be needed?
Thanks in advance for your help.
Totally off-the-wall suggestion. Is there any way that a piezoelectric
gas lighter could be used or modified to charge the dosimeter? No
batteries required and only a dollar or two to buy.
https://www.amazon.com/Jordan-Radiological-Dosimeter-Chargers-Bendix/dp/B076746ZG8 I actually have this set (only four pens, however). It came as a set with a geiger-counter that I snagged at a flea.volts DC. That should not be too difficult. But, of course, you would need some power from some source. That, sadly, is the nature of those beasts.
If you want to make the charger stationary, it is simply a matter of delivering the proper DC voltage - which I dimly remember is supplied by one D-sized cell in the container. And as these were based on conventional Leclanche cells, that would be 1.56
Peter Wieck
Melrose Park, PA
Totally off-the-wall suggestion. Is there any way that a piezoelectric
gas lighter could be used or modified to charge the dosimeter? No
batteries required and only a dollar or two to buy.
With that in mind, how about one of those anti-static devices for records?
https://www.amazon.com/Zerostat-Anti-Static-Instrument/dp/B074XLBNDD
Bit pricey, however.
Peter Wieck
Melrose Park, PA
I am in the process of trying to set up a reliable dosimeter charger
system for a relative. The type of dosimeter I'm speaking of are the
pen looking devices that are zeroed after exposure to radiation so that
they can be reused over and over agin. There are a couple of types of "chargers" used for this process:
https://pim-resources.coleparmer.com/item/l/radiation-alert-the-charger-radiation-dosimeter-charger-8192200.jpg
https://i.ebayimg.com/images/g/9X0AAOSwcm5fNxcf/s-l1600.jpg
I personally own the first type above (the coleparmer unit). It doesn't need power, and uses a piezoelectric element that is pressured to
produce charging, then can be bled off until the dosimeter is zeroed. However, I got mine in a trade deal with a bunch of other equipment, so
it was essentially free. What I like most about it is that it doesn't
need any kind of power source for charging dosimeters unlike the second yellow one above that needs a 1.5V battery.
It is the type I own that I had hope to obtain for a relative too, but
at the prices I see them go for, it is out of the question! So, that
leaves the yellow ones that use a 1.5V battery. I do happen to own a
couple of those, but find them much harder to use than the trigger
charger. I was considering modifying it so that it wouldn't have to use
a 1.5V battery. Only a bendix 643 (CDV 750 model 1) used a pump charger that must have been similar to the trigger charger I use, but I have yet
to see one in the used marker. How would you go about modifying an
existing charger so no battery would be needed?
Thanks in advance for your help.
I don't have a suggestion, but I am curious - what use has your relative found for the dosimeters? I have one without a charger, but it was
charged when I received it and has barely discharged in the many years
that I have owned it, and I hope it never will (or not when I am near it anyway!) Its full-scale reading is a fairly decent fraction of a lethal
dose IIRC.
On 1/18/22 12:36 AM, Chris Jones wrote:
I don't have a suggestion, but I am curious - what use has your
relative found for the dosimeters? I have one without a charger, but
it was charged when I received it and has barely discharged in the
many years that I have owned it, and I hope it never will (or not when
I am near it anyway!) Its full-scale reading is a fairly decent
fraction of a lethal dose IIRC.
It's ok, I've been asked that before. Well, with things being what they
are in the world lately, I've been trying to set up not only myself, but
a relative or two as well with some radiation monitoring systems. The
idea with the pens and chargers is that, in the awful event a large
scale nuclear event occurs, that we might increase our chances of
survival. As I write I doubt that our odds would be that get to even
get to the point of monitoring (we are all within 50 miles of major
cities and military bases), but just as a precaution. I have seen all
of this CD equipment for years and decided to go with a bunch of the
pens and chargers in a trade. Something high level is definitely needed because most "geiger counters" would be useless after such an event. We
all have geiger counters, but I doubt any of them would even survive an EMP. I have some low range pens as well, only up to the 200 mR range
that might come in handy for less severe events, such as atomic plant incidents. Oh well, these are just some ideas and precautions that have cost next to nothing to try implementing. I don't really trust that batteries would be all that reliable after a crisis, which was why I was looking for a non-powered way to allow the 1.5V chargers to still work.
No, I'm trying to get away from having to use the battery. Something
like a crank generator. The original Bendix model from the 50's had
such a generator built in. It is 1.5VDC, yes and a single D cell.
One more hint. If you're really preparing for a full blown nuclear
disaster, make sure that your equipment can operate in very high
levels of radiation. Most equipment does not do well, will overload
easily, and produce either no reading or a useless reading.
One more hint. If you're really preparing for a full blown nuclear
disaster, make sure that your equipment can operate in very high
levels of radiation. Most equipment does not do well, will overload
easily, and produce either no reading or a useless reading.
They don't respond well to low levels of radiation (background, NORM,
uranium glass, Fiesta ware, etc.).
we have a mil.spec. counter with an "alpha-detector" window - an area of
very thin material that may be exposed by twisting a cover on the head. And a small side-detector as well.
https://thumbs.worthpoint.com/zoom/images2/1/0116/22/pdr-27s-radiac-set-radiation-detector_1_11509f068d2a4a64e50f0476e7ebab00.jpg
is a picture of a similar device. Picks up radium-containing glazes nicely.
In article <anfeugpj7a2pdsg1m2tr3kp333kb04p6gc@4ax.com>,
Jeff Liebermann <jeffl@cruzio.com> wrote:
One more hint. If you're really preparing for a full blown nuclear >>disaster, make sure that your equipment can operate in very high
levels of radiation. Most equipment does not do well, will overload >>easily, and produce either no reading or a useless reading.
As I understand it, that's the reason that most of the radiation
survey meters in the old Civil Defense kits were ionization-chamber
types. They cover ranges of radiation which are actually harmful or
lethal to humans in a relatively short amount of time (minutes to
weeks). They're "no, you really don't want to be here, get the hell
away" devices, just like the dosimeters.
They don't respond well to low levels of radiation (background, NORM,
uranium glass, Fiesta ware, etc.).
Their biggest disadvantage is that they operate at such high
impedances (to measure leakage in the ionization chamber) that they're
very sensitive to moisture. As I recall, they're supposed to be
"baked" periodically to make sure they're dry, and then stored sealed
in plastic with a dessicant pack.
The old Civil Defense kits tended to come with a bunch of these
ionization meters, some dosimeters and chargers for them, and one
Geiger counter. The Geiger was intended more as a training device
than as an actual "when the bombs drop" tool, due to the problem
you mention... in an actual fallout zone, Geiger counters and
scintillation detectors will probably saturate and read low or
zero.
Today, methinks that some of the higher end radiation survey meters
have an PIN diode gamma ray detector for the higher doses: ><https://www.ssdi-power.com/products/special-devices/radiation-detector-pin-diode/spd9441.html>
<https://www.ssdi-power.com/media/pdf/RC0130B.PDF> ><https://www.ssdi-power.com/media/sp_pdf/AN2011-01_Radiation_PIN_Diode.pdf> >Sensitivity is marginal, but it doesn't saturate at higher doses. At
those high levels, it's use is mostly as a dosimeter, not a
disintegration counter. ><https://www.maximintegrated.com/en/design/technical-documents/app-notes/2/2236.html>
etc...
The photo also shows the quartz wired dosimeters and readers. The
geiger counter is for fairly low radiation levels. The ionization
chamber is for fairly high levels. I've been told that if I need to
use the ionization chamber device, I'm already dead.
Their biggest disadvantage is that they operate at such high
impedances (to measure leakage in the ionization chamber) that they're
very sensitive to moisture. As I recall, they're supposed to be
"baked" periodically to make sure they're dry, and then stored sealed
in plastic with a dessicant pack.
Nope. The ionization chamber is hermetically sealed (sealed by a
hermit): ><https://www.survivalmonkey.com/resources/victoreen-cd-v-715-instruction-and-maintenance-manual.267/download?version=268>
"The ionization chamber is hermetically sealed to eliminate changes in >sensitivity due to changes in air pressure resulting from altitude
changes, temperature changes, and moisture effects". (Pg 3)
However, I have seen problems with the phenolic paper PCB used in most
early units. The PCB absorbs enough moisture to cause high resistance >shorts. A few minutes in a toaster oven usually solves the problem.
If I see some flux left on the PCB from a previous repair, I clean it
off with water and alcohol separately, and then coat the area with
some manner of conformal coating or high-voltage corona dope.
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