Geiger Counter Test Card

Showed 400CPM on a Pudibel NR-750 radiation monitor. Background was 10 CPM +/-5 I left the radiation test card in the outer plastic jacket with the paper spec sheet inside on one side of the source card. So that is two protective plastic jackets. With the least amount of obstructions it measured 400CPM. the other side was around 290 to 300. The meter was placed on the source about the center Radiation drops off at about a foot above the center. For storage, I put it in a plastic tackle box in the middle using the two storage shelves to hold it in the center. The meter measured 10CPM directly over the card so I think this is a safe storage method. I wrote Radiation Test Source on the box top and side.

Between the two samples from the Geiger Counter Radiation Test Card and The Uranium Ore my handheld Muller Tube GQ GMC-800 geiger counter averages were: CPM=3,093 - μSv/h=20.11 - mR/h=2.01 - CPS=65 The readouts would be even higher if I took the samples out of the plastic but I actually sealed them with an extra 4 mil airtight Plymor bag before testing. I'm impressed by these samples. Great way to check your background radiation gear and examine radioactive minerals and anything else you want to test. The alpha radiation is rated at CPM 19,000 if you are using an alpha capable probe for the readout of the Uranium Ore. Happily nuclear, Starry

It works. Well, that was fun. With background less than 2 uSv/hr, this is at least 25 times background. I'll be sure to put it somewhere safe, not as far away as the smoke detectors though, those were pretty nasty. I've stopped using my Phaltzgraff plates since they were pretty hot. Too bad, I liked them. Two feet away, and the radiation is completely undetectable. The Geiger counter reads 0.075 uSv/Hr, which is better than normal for background radiation. This is really odd and makes me wonder if the little radioactive goop is sucking the local radiation in, to spurt it out more powerfully. That could be a great marketing ploy: protect your home from radiation, install this goop on the window, or something. It would probably be debunked, like when they all used to drink radioactive water in the old days, like around 1900 maybe, and had pitchers in which were holders for their thorium or uranium, or worst of all, Radium. They would bathe in nuclear springs. They would play on swings, not wear seatbelts, smoke cigarettes, etc.

Very nice Geiger counter, works perfectly for a guy like me who loves nuclear physics!

I got a reading of 1.17 uSv/hr with my Radex 1503+ device which seems to match the pics of other reviewers who have the red dot card. Those who got the yellow ones look like they read much higher. Don't expect too much, it's not for calibrations, just to test functionality.

So the key to this test card is that to get it to register properly, you have to have it *as close as possible* to the detector tube (and the openings that allow entry of the particles into the meter). If you simply set the meter on top of it (GQ 300 or 500+) you'll only get a fraction of what you ought to. You need to hold the blob on the card right up to the openings at the bottom of the meter to get the proper reading. The difference between simply setting the meter on the card (for me) and the RIGHT position was 50 CPM (not much above background) vs >800 CPM. Even two or three inches away from the card will drop you down below 100 CPM. Worth remembering.

The card has just enough (whatever) to make my counter become very active when it is within about 1 foot(300mm) of tube. I won't be keeping it in my hatband but I don't have any concerns having it. I have a couple of Geiger tube devices that I wanted to see do something interesting. My newest one (Arduino based) might have just been random clicking noises and I'd have never have known. Now I do know it does work. I don't live very close to any nukes but if I did... My other counter is an old surplus civil defense giant with a copper chamber. It's all old skool discrete components and came with a schematic so I might res it up for a nostalgic wayback experience. I removed the battery and cleaned the mess back in the 1980's. It is designed to still function after whatever 'event' may happen to make it useful!!! Back on topic, the card is as advertised! IMneverHO

I don't know about the accuracy of my Geiger counter, I'm just happy to see that it somewhat works. I got a reading of 5 micro-Sv/hr just throwing my device on top of the test card without much thought to optimum placement. I'm going to play around with it a bit more to see what I can get. So far, I'm happy.