Reply With QuoteNot a pipe dream.
Kindest Regards, " The Druid ".
Radiation detection devises
Last night in a chatroom I spoke to a person (American) who lives in China and makes a 'Personal Radiation Detection' devise.
He gave me a link to the US Sears company and there is this pen shaped 'detector' on sale for around AU$30.
His claim is that when you 'activate' it a Red LED flashes as it 'calibrates' the devise for background radiation then when its done, you can then pass it over food items both solid and liquid (do NOT immerse) and if the LED comes on, the item is 'Radioactive'
This is a tube with no dials,bells,whistles or sirens, just 2 LED's.
I remember years ago Electronics Australia or the other had a DIY for a Geiger counter but it wasnt cheap and needed a bit of skill to construct, well beyond my capabilities but certainly not as simple as what this devise appears.
He also claimed to have Certification that it works from two 'Scientists' who were/are at Los Alamos, the US A Bomb testing facility.
He also claimed to have sales totaling 2.5 Million units but then, those who bought those End of the Universe/Millenium Bug (2000) survival kits were American too, wernt they ??
And look at those 'Dooms Day Preppers', ohhh boy.
This gadget may well 'detect' radiation the same was a fluorescent tube gets 'excited' near a RF transmitter but is it really a level of radiation to be concerned about?
What I am trying to say here is I think this 'Detector' walks the Fine line between he cant prove it does and I cant prove it doesnt.
Maybe I am being hypercritical but first he's American, its made in China and sold well below what even a basic certified Geiger counter sells for.
My knowledge of radiation is like most, bugger all.
But I dont think I would want to trust my well being to a Chinese made $30 detector, would you??
I stand unequivicably behind everything I say, I just dont ever remember saying it !!
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Not a pipe dream.
Kindest Regards, " The Druid ".
While I have never seen or had contact with I am aware of these and other devises used in medical situations but this Pen he had has nothing like any of these features.
I will try and find it via Google if I can.
****************************************
It is an AVANTI Personal Radiation Detector shown in a Sears Catalog but the 'page' closes after momentarily displaying the devise which makes me think it is a prohibited Export from the USA.
From the picture and written details it does NOT work in any way similar to those shown by Beer4life.
As I said before, all it has are 2 LED's that after 'Calibration' flash to warn you an item is allegedly Radioactive.
It has no meters or 'TellTails' to show any Radiation levels it may encounter.
For this Avanti devise to work, you must be 'Up Close' to the tested item.
Last edited by gordon_s1942; 14-10-12 at 02:28 PM.
I stand unequivicably behind everything I say
Yep, what he is describing is a pretty standard dosimeter. I can prove they work very easily. You might even have something in your house that works by the same principle.
These devices have been in existence since WWII. They're simple and effective though their use is only for a short period, about a day. They are designed to be used during a shift and then recharged
while idle between shifts.
They work on the principle that statically charged objects will lose their charge when exposed to ionising radiation.
If you have a graphite brush used for cleaning old vinyl records you might detect that it is radioactive. Typically they were doped with a small amount of Polonium 210 which discharged the static from the brush.
Dosimeters and Ion geiger counters are just types of electroscope.
This experiment is sometimes demonstrated for high school students. An electroscope is charged and then a radioactive source is placed near the electroscope's charge plate.
The students can then see the electroscope slowly discharge.
Older dosimeters don't use an LED or anything fancy. They just have a small needle which moves with respect to the charge in the device.
I would guess that the LED version has two capacitors in it. One for the ion chamber and the other I expect to be shielded with a FET and LED.
If the ion chamber discharges, then the FET allows current to flow from the second capacitor to the LED via a resistor. Damn simple, but I prefer the older style.
$30 is a bit steep when you can buy a bunch of the older units with a charger surplus for about the same price.
There are better dosimeters which are more sensitive and give active warnings. I have a small electronic one which is about the size of a postage stamp. I've forgotten the name.
They're pretty good and reasonably sensitive. They use a PIN diode as the detector. The amount of current crossing the PIN barrier can be controlled with photons. The PIN diode doesn't care
if those photons are IR, light, UV, X-rays or Gamma rays or beta/positrons. PIN diodes are also sensitive to mechanical shock, so they can be tested by shaking the device hard or tapping it lightly on a table.
It's a cute little device, but rather pointless for my uses. There is only two places I've managed to set it off. In my storage cupboard and while having an X-ray.
Dosimeters are blunt devices for detecting radiation. You just would not bother buying one unless you had a specific interest in radiation detectors like I do, or you work with very large amounts of ionising radiation.
There are some dosimeters made for security operations in places like airports.
This is one of this is one of those units.
As for detecting radiation from trivial sources like food. Dosimeters just don't cut it. They're a complete waste of time.
Pancake GM tubes are about the best task for the job short of processing the food and running as sample of it through a mass spectrometer looking for trivial isotopes.
If you're going to play with geiger counters, then there are a few types to choose from.
For the task you've described, a pancake tube or a mylar window GM tube will suffice.
The EA kit used a mylar window GM tube and you can buy a similar tube like an LND712 from Jaycar. They'll sting you $199 for them, but you can get them on ebay for about $90.
How much you spend on a geiger counter varies depending on it's type. $100 for a simple beta/gamma hand held detector using something like an SBM20 tube is not unusual.
Oatley Electronics have a GM kit. It comes with a rather insensitive glass GM tube that's good for gamma or hard beta.
The counter works better if you change the tube to an SBM20 or it will detect Alpha particles if you use a mylar window tube like an LN712 and even more sensitive with a pancake tube.
Yes I am an agent of Satan, but my duties are largely ceremonial.
BillyGoat (15-10-12),gordon_s1942 (15-10-12)
Trash, many thanks for that information.
I am not Blase' about the potential dangers of Radiation but I feel this fellow and his 'Detector' is riding on the current wave of fear particularly after the Tsunami that severely damaged the nuclear power station last year as he specifically mentioned the 'Japanese Rice Farmers' in our conversation.
As I said before if I was worried about Radiation I would want something more 'up market' than this thing.
I stand unequivicably behind everything I say
Ah yes, well he's not the only one. There have been no shortage of fools and people willing to sell them placebos to fuel or ease their fears.
The sales of Iodine tablets to stupid Americans went through the roof. The sale price of geiger counters on ebay tripled overnight. Counters which used to sell for under $100 suddenly sold for over $300.
Prices have settled back down now, but they are still elevated by about 50% on what they used to be.
I am more blase' about radiation. I have a reasonable collection of radioactive stuff. It scares the shit out of most people. I guess I'm just not that easily scared.
When you understand the monster you can control him. Steve Irwin was never going to be killed by a croc.
Yes I am an agent of Satan, but my duties are largely ceremonial.
Their son could have been though.Originally Posted by trash
Ah yes, well he's not the only one. There have been no shortage of fools and people willing to sell them placebos to fuel or ease their fears.
The sales of Iodine tablets to stupid Americans went through the roof. The sale price of geiger counters on ebay tripled overnight. Counters which used to sell for under $100 suddenly sold for over $300.
Prices have settled back down now, but they are still elevated by about 50% on what they used to be.
I am more blase' about radiation. I have a reasonable collection of radioactive stuff. It scares the shit out of most people. I guess I'm just not that easily scared.
When you understand the monster you can control him. Steve Irwin was never going to be killed by a croc.
He got his just deserts for his egotistical bravado.
B4Life, If your referring to Steve Irwin's death being a 'Just desert' I find that remark grossly insulting and totally uncalled for.
Irwin did what hundreds of others have done before by swimming over that Stingray and for it to react as it did as far as I could tell was totally unexpected.
I worked on the NSW State Railway and one of the early jobs I did (1960)was 'Shunting' trains where I had to couple trains together using the old style 'Hook and Link' which meant I had to stand between the buffers to drop the Link over the hook as the vehicles came together.
Injuries ranged from cuts and bruises to being crushed to death in a job that today isnt allowed under OHS rules so would say my predecessors got their 'Just Deserts' doing their job?
Personally I would ask you to edit out that comment completely and I will remove my return comment.
Trash, I was going to say that your no different (Blase' to Radiation Risks) to many whose job's pose an element of risk that many find unacceptable, like mining or high rise construction but again thank you for the very interesting information
I stand unequivicably behind everything I say
weirdo (16-10-12)
I wasn't a huge fan of Irwin either but find that remark of pest4life a bit silly and uncalled for.
Regardless of whether I'm within the Edit Time Frame or not.
I'm aghast at your attitude to his purile disregard for his prodgeny.
WITNESS this:-
Am I to understand that you condone this blatent exibitionism????
I expect an apology and withdrawal of your comments as they did not appertain to my post!!!!!!!
Last edited by beer4life; 18-10-12 at 11:03 AM.
Ber4life, Dont hold your breath waiting for any apology from me as YOU made the comment re his Death being a 'Just Reward' and I still say it is grossly insulting.
I rarely watched any appearance by Steve Irwin unless it was on a news item or in an advertisement and as such I never concerned myself enough to either condone or criticise his actions.
I doubt many would disagree that the stunt he did with the child was plainly stupid and could have had catastrophic consequences if he had misjudged by the tiniest amount and no doubt that was clearly brought home to him by the huge volume of criticism it caused but to associate it with his later death I find outlandish.
I stand unequivicably behind everything I say
Nar... Steve was an expert croc handler ... they're large dangerous animals and I will avoid them at all cost.
I was working in NT in Kakadu when my boss told me to get out and check the depth of the creek crossing ..... No F%%%ing way... I don't care that it's just a puddle...you get out, I'll drive !
He also suggested I could swim at Dundee, he would be on the beach with a shotgun. I suggested I would have a lot more fun if I watch him get taken by a croc while I held the gun.
Steve with Bob in his arms I don't find alarming. He knows the croc better than anybody else. If it was me holding the kid.... I would have chucked the kid to the croc and made my escape !
It's the public's opinion of stupidity that has changed over the years.
Would I do what Steve did. I'd say no, but then... I have had others say something in other circumstances.
Like my little fella shooting a gun. He first shot a gun when he was two. Now some people would say this was dangerous and stupid.
I challenge them to demonstrate how ? Chances are I will get to see some cotton wool fvckstick shoot themself in the head.
In no way was it dangerous. I can remember the first time I shot a gun, when I was three.
So, my parents must have been as stupid as I was. I would suggest much more so but not for that reason.
No, my little fella thought it was fun and he has an understanding that a gun hurts people and things.
He has a healthy caution about them and knows that dad makes them safe and fun and that they aren't toys.
It's more discipline than he gets from other members of the family.
It's strange that his uncle bought him a nerf gun, he does not like the idea of shooting his uncle with it even when asked to do so.
The cat and the furniture get a pounding.
Growing up, I was always exposed to guns especially in the Airforce cadets where I think I had an SLR in my hands more often than not.
These days seeing a kid with a semi-automatic assault rifle would send some members of the community into a tailspin.
I can remember walking into an RSL with the rifle for an ANZAC day service and I held the door open for two old ladies.
The five old guys at the bar were more concerned that I didn't get my hat off quick enough, not that I had an L1A1 under my arm.
I have a friend who I consider to be a borderline idiot. He's not the smartest guy on the planet, but he does handle snakes (this only reinforces my statement).
Do I trust him to hand a brown snake and not get bitten. Sure do. What are my chances of handling a brown snake without a shotgun or a visit to the hospital ?
My solution .. I don't handle snakes.
There's lot of dangerous stuff I do. Hang gliding, Paragliding, technical scuba diving. I have soooo many cool ways to die.
I work at heights and with radiation.... I've got LOTS of tickets in the death lottery !
I collect radioactive stuff. What do you suppose my chances are of getting cancer or dying from a cancer ?
Actually, they're pretty good. Chances are 50% that I will get cancer and about 33% that I will die from a cancer.
Oh... that's the average for everybody in Australia. So I'm not really that worried by some trivial radiation.
People living in certain parts of the world receive a LOT more than I do. Even Air crew get more radiation than I do.
Taking a geiger counter on a plane is great for a laugh. Just don't let the other passengers hear it.
I have certain things I do. While it's safe to handle any of my samples, I avoid it. Handling them once is harmless. Handling them repeatedly over time is like buying a systems ticket for that death lotto.
I'd love to put them on display in my home. I know some people who do. That is a little too much for me. While the radon exposure is still trivial, I've measured how much radon my samples generate.
No way damn it ! I've considered air tight displays, this would be great, but any time they were opened to be cleaned etc... oh... that would be bad !
Back to the bottom line ..... Average People are shit scared of radiation.
People are and always will be scared of things they do not understand. Whether it is Radiation, Crocs, Snakes, Guns, Fairy Floss, Spiders, Flying etc.
If I'm going to die, it's going to be from doing something stupid or because somebody else is doing something stupid.
I'm not going to die from boredom.
Yes I am an agent of Satan, but my duties are largely ceremonial.
damn double post again .... more forum issues
Last edited by trash; 19-10-12 at 12:01 AM.
Yes I am an agent of Satan, but my duties are largely ceremonial.
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