If you have a counter already just follow the directions below. If not see thermino below to build your own counter or find a unit somewhere else.
You can perform these tests with most any counter but the better the counter, the more accurate the results will be.
The thermino setup will actually tell you what the radioactive material(s) found are. A GM test will only tell you there is something there, not what it is.
Don't forget to change the language to English by clicking the flag at the top right of the page if you are interested in building your own counter. If not, and you have a counter, skip this section and read on below.
It's way more simple than you think to perform these tests but there are some details you must follow to get accurate results.
[url]
http://www.theremino.com/blog/gamma-spectrometry [/url]
If you are using a simple GM counter just test the food / water for several hours inside a shielded container and divide the minuets tested by the end number to get the average. Use the CPM setting if you have a choice of measuring units on your counter. Anything over the empty container test average will be radiation coming from the food / water sample. It's hard to detect low levels in food so you need to test "overnight" and place the sample inside a shielded container (or you can purchase some lead bricks and build a "cave") to detect it with any accuracy. Place the counter as close to the sample as possible without touching it.
Use NO plastic bags or food packaging with these tests. You can place a small paper plate in the bottom of the container to hold the food tested. Another good way is to use a disposable tupperware type container if you wish and place the counter on top (without any lid). You can also simply cut a hole in the plastic lid where the detection window is on your particular counter. If your counter does't have a window it's best to not use the plastic containers lid at all. Get your counter as close as possible (should be less than 1/4 inch.) to the sample with nothing between the counter and sample. The closer the better!
Here's a article of a high school student that used this method with a inspector GM counter and won the science fair at her school!
She used the pressure cooker method... Notice the pot on the table behind her in the photo.
[url]
http://metronews.ca/news/calgary/982233/[/url]
A heavy pot and a counter with a computer and some free software is all you really need to get started.
Let's say you want to test a steak and then (hopefully) eat it later...
You can even test food in the fridge by placing the pot with the counter (switched on and operating) inside the fridge for a few hours (to allow them to cool to the fridge temp) before running any tests. Just make sure you perform the empty container test after the counter and pot have adjusted to the temperature in the exact location you plan to test food. If you test for 8 hours then it's best to do a empty container test for 8 hours also.
Note: Your total counts will be lower in the fridge due to lower temp and added shielding.
Remember: If you use a paper plate or other container inside the pot you have to place them inside for the empty test as well. So everything should be identical including the exact placement of the counter minus the food sample for the empty test.
You must test the empty container first for the average background reading...
Then test your food and look for a higher average than the empty test average. The difference (if any) is radiation in the food tested.
Example:
Start the empty test and record the EXACT (Min AND Sec) time you started the empty test and go to bed. Next morning record the count total and the EXACT (Min AND Sec) time spent in the container. Place the sample into the pot, record the EXACT (Min AND Sec) time you started the food test and go to work. When you get home you will have a long count to average. I recommend you test the empty container and then test food the exact same amount of time but it doesn't have to be exact it just makes it easier to see the difference in the averaged results.
If you use the CPM (counts per minuet) setting divide the total counts by the minuets tested so time the test in whole minuets with no seconds remaining when removing the counter. With CPS (counts per second) divide by the number of seconds tested.
Start with rice as rice is a water intensive crop that is dried and should give you some good experience testing... You can even grind the rice up first with a coffee grinder for more accurate reads. The high school student above tested seaweed and other foods sold in local stores and found some alarming results.
Test anything you want with this setup and find the radioactive content of the item. Try your pets "poop" (let it dry for several days) if you have one for some interesting results.
When you test please let me know what you tested and what (if anything) you find.
And don't panic if you think you found something testing with a simple GM counter. There is allot of this stuff floating around and I will bet you will find something sooner or later. Sometimes it's nothing and sometimes it's a learning experience for future tests. If for example you test a banana you will find extra counts from the potassium and this is not a problem as this potassium is a natural element.
Try some ground up dried banana chips for a interesting test.
Always let me know what you test as there are ways to figure a natural or man made source contained in the food. For example you should look up the potassium content of the food you are testing...
[url]
http://apjcn.nhri.org.tw/server/info/bo ... ata5b.html[/url]
Here's a wiki on banana content...
http://www.ask.com/wiki/Banana_equivalent_dose?lang=enIf (and when) you do find something let me know and I will try to help you understand the results.
Always list these details in your posts and e-mails to anyone:
1) The type and model of the counter you used
2) The type of container you tested in
3) Start and stop times for both the empty test and the food test
4) The readings (total counts) from both the empty test and food test
5) The tested items description
Let me know if you need any more info...
I will try to help you get more accurate readings if need be.
Send your results to:
rads@lamarsworldmall.comBelow is what you need to get started...
There are several free software packages out there, here's a simple one to get you started... If you test with the counter hooked up to a computer just run the wire through the small hole in the top of the pressure cooker. With a heavy copper pot simply remove the lid handle, run the wire through the hole and cover with a piece of tape.
[url]
http://www.imagesco.com/geiger/geiger-graph.html[/url]
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The simple way...
Use a old metal cooler if you have one or can find one (the old coleman cooler shells were made from a galvanized metal lead/steel mix) and place a copper cook pot inside it... The copper pot will help shield from outside XRays. This is not a scientific method but can be quickly, safely and cheaply setup.
Try a old pressure cooker (like the ones used for canning vegetables) if you (or the grand parents) have one.
These older pressure cookers work because of the metal alloy(s) used to prevent explosion in the event of "over pressure" / normal wear over time and are airtight.
Both of these work good for eliminating false reads.
Run a couple of full tests inside the empty container (with the cooler setup the pot needs to be inside) and save the data for (baseline) reference. When you begin testing you should test the empty container for contamination regularly.
crystalrows wrote:
How I can create a homemade Unit?