GQ Electronics Technical Support Forum


GQ Electronics Technical Support Forum
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
Password:
Save Password
Forgot your Password?

 All Forums
 GQ Electronics Forums
 2.GQ Geiger Muller Counter
 Sensitivity of GMC-300E+
 New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

SolarSurveyMonitor

Mexico
13 Posts

Posted - 05/19/2019 :  11:44:29  Show Profile  Reply with Quote
I'm at sea level now, kinda desert environment but noticed weird readings. I got uncommon readings yesterday and was in doubt that the GM tube is photosensitive. On areas with solar light reflected I got readings about 60~110 CPM. Then I rotated counter for a moment to get tube lit with solar rays and started to click up to 500~600 CPM. (What a discovery!)
Today I just surveyed 28.86295373640999,-112.00699800256348 and got 40~50 CPM @ 1 m above ground. CSV log: https://drive.google.com/file/d/1yjV5gh4eg5y7ij-TTlHXnp_upi6pI043/view
A concern is if those readings are accurate, I'm guessing lots of beta radiation, or a hole in ozone layer, perhaps other things.
@ 12:42 GMT -7 indoors 38~49 CPM, 12:43 down to 12~23 CPM.

Edited by - SolarSurveyMonitor on 05/19/2019 11:48:53
Reply #1

EmfDev

642 Posts

Posted - 05/20/2019 :  08:35:24  Show Profile  Reply with Quote
There are report before that some M4011 tube are sensitive to light. I think also if the voltage is too high, it can affect the reading.
Go to Top of Page
Reply #2

SolarSurveyMonitor

Mexico
13 Posts

Posted - 05/22/2019 :  07:54:55  Show Profile  Reply with Quote
Ok, I looked around and I found posts about this issue. It's mostly sensitive to from early blue wavelenght to UV, like CFLs and bug killer lamps. On darkrooms doesn't seem to affect true readings. Testing with gas mantles has the same average ~750 CPM as I tested weeks ago.
Go to Top of Page
Reply #3

EmfDev

642 Posts

Posted - 05/22/2019 :  09:12:54  Show Profile  Reply with Quote
In a normal room with lights on are the readings the same compared to when you turned the lights off?
Go to Top of Page
Reply #4

SolarSurveyMonitor

Mexico
13 Posts

Posted - 05/23/2019 :  22:21:12  Show Profile  Reply with Quote
Almost same. Because (device) average CPM varies about 1.3 CPM, I I'd like to test it further along some days with different types of light, CFLs, LED, incandescent, to collect sustained evidence. By the way, on GMC-300E+ 4.50, what's the time frame for calculating average CPM?

Edited by - SolarSurveyMonitor on 05/23/2019 22:24:34
Go to Top of Page
Reply #5

EmfDev

642 Posts

Posted - 05/24/2019 :  08:20:40  Show Profile  Reply with Quote
Average CPM is the total counts (since you turned on the device) divided by the total number of seconds times 60.

Maybe try to use the Timed count feature and check total counts with in a time interval like 1 day instead of just the CPM.
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
GQ Electronics Technical Support Forum © Copyright since 2011 Go To Top Of Page
Generated in 0.11 sec. Snitz Forums 2000