| T O P I C R E V I E W |
| Discopotato |
Posted - 05/05/2025 : 02:54:49
Hi everyone
I recently just bought a GMC-600 but when I trst against a uranium glass bowl I have the responds very well to black light the max reading im getting is 36cpm
I don't know, I no expert at all but shouldn't I be seeing atleast 500cpm on something like this? |
| 5 L A T E S T R E P L I E S (Newest First) |
| Discopotato |
Posted - 05/10/2025 : 03:24:21
The uranium source i used was a glass bowl i bought, advertised as uranium glass.
The counter back plate was removed and placed in a snap lock sandwich bag and than placed inside the bowl on my loungeroom table
For reference the background here is around 24cpm and 80-90 in the bowl
If i have the back plate on i get around 36cpm for memory. |
| ihab17 |
Posted - 05/09/2025 : 12:02:10
Either you do not have a real Uranium sample, or your device is broken (in case you were using it the right way). Can you post a short video somewhere to see what and how are you using it? |
| ullix |
Posted - 05/09/2025 : 02:50:53
What radioactive source did you use? How was the counter place in your room? CPM80-90 would be a lot for just background.
The sequence of clicks is a random distribution. To be more prceise: a Poisson distribution. Google for it, and/or use GeigerLog to see it yourself.
The "Fast Estimate" is the worst feature of the GMC counters I can think of. I urge erveryone to switch it OFF by setting it to 60 sec.
|
| Discopotato |
Posted - 05/07/2025 : 13:31:09
So in the mean time i pulled the back cover of the gieger counter and put in a plastic snap lock bag and the readings came up to roughly 80-90cpm but the ticks are not a consistent tone. Is that normal?
I did have a quick read of the article you directed me too
Also what is the best setting to use for fast estimate, dynamic? |
| ullix |
Posted - 05/05/2025 : 04:06:33
36 CPM is barely background, and could well be just electronic noise with a broken Geiger tube.
Can you try some other stuff as readio-source? Potassium, e.g. If you are unfamiliar, I suggest my article "Potty-Training" as a primer.
https://sourceforge.net/projects/geigerlog/files/Articles/
|
