GQ Electronics Technical Support Forum Active Users: / Visits Today:
Highest Active Users:
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
 500+ False readings

Note: You must be registered in order to post a reply.
To register, click here. Registration is FREE!

Screensize:
UserName:
Password:
Format Mode:
Format: BoldItalicizedUnderlineStrikethrough Align LeftCenteredAlign Right Horizontal Rule Insert HyperlinkInsert EmailInsert Image Insert CodeInsert QuoteInsert List Spell Checker
   
Message:

* HTML is OFF
* Forum Code is ON
Smilies
Smile [:)] Big Smile [:D] Cool [8D] Blush [:I]
Tongue [:P] Evil [):] Wink [;)] Clown [:o)]
Black Eye [B)] Eight Ball [8] Frown [:(] Shy [8)]
Shocked [:0] Angry [:(!] Dead [xx(] Sleepy [|)]
Kisses [:X] Approve [^] Disapprove [V] Question [?]

   Insert an Image File
Check here to include your profile signature.
    

T O P I C    R E V I E W
CrocodileDandee Posted - 07/14/2020 : 03:38:58
I just realized I can bring up my Geiger counter far over 100 CPM just using in a plastic case rubbing the case from outside. Why? Is that why there is not a clear plastic cover for this device available? I turned Tube 1 only on or both, it doesn’t matter I can easily just with rubbing the plastic from outside make my Geiger counter getting wild....
P.S.: it happens only where the black tube is.
7   L A T E S T    R E P L I E S    (Newest First)
CrocodileDandee Posted - 07/14/2020 : 19:50:04
Many thanks for your explanation. I will try today if I can generate the same electric field in a ziplock bag. It might be a good alternative to use one because then I can just chuck it out after my trip.
EmfDev Posted - 07/14/2020 : 09:49:32
Rubbing the plastic can generate very high static EF (Electric Field) which can affect the tube voltage.
Damien68 Posted - 07/14/2020 : 05:27:17
to protect from dust, it is important especially if you go to contaminated areas, you can use a simple ziploc bag
CrocodileDandee Posted - 07/14/2020 : 05:09:28
quote:
Originally posted by Damien68

with certain plastics, rubbing it make electrostatic charge. this must cause discharges passing through the tube and especially through its current detection circuit.
These discharges must then be interpreted as detected particles and increment the cpm counter. we could try the same thing with an "antistatic bag" or "ESD bag".

as said stargazer40, there could be problems of capacitive coupling between the tube cathode and an external reference (like a hand). but the fact of rubbing would have no influence.
but in general cases it is true that is better to avoid putting the tube too close with your hand, especially if you are in an environment with significant electromagnetic radiation.



Thanks for your response and explanation.
Damien68 Posted - 07/14/2020 : 04:50:53
with certain plastics, rubbing it make electrostatic charge. perhaps this cause discharges passing through the tube and especially cross its current detection circuit.
These discharges can be interpreted as detected particles and increment the cpm counter. we could try the same thing with an "antistatic bag" or "ESD bag".

as said stargazer40, there could be problems of capacitive coupling between the tube cathode and an external reference (like a hand). but the fact of rubbing would have no influence.
but in general cases it is true that is better to avoid putting the tube too close with your hand, especially if you are in an environment with significant electromagnetic radiation because the hand would act in some way 'like an antenna'.
CrocodileDandee Posted - 07/14/2020 : 04:14:19
quote:
Originally posted by Stargazer 40

The reason the black tube is black is to prevent light from activating the tube. The more sensitive a GM tube is, it is generally more sensitive to other triggering energy. Not sure if you are creating some capacitive effect by rubbing the plastic cover, but that seems likely. So don't. ;-)



Thanks for responding. I will have to use it out of the case then. That’s disappointing, because I tried to find a plastic clear case, which is it turning not into a good idea... I wonder how other users are using theirs when travelling in dusty and bad weather conditions outside...
Stargazer 40 Posted - 07/14/2020 : 03:59:07
The reason the black tube is black is to prevent light from activating the tube. The more sensitive a GM tube is, it is generally more sensitive to other triggering energy. Not sure if you are creating some capacitive effect by rubbing the plastic cover, but that seems likely. So don't. ;-)

GQ Electronics Technical Support Forum © Copyright since 2011 Go To Top Of Page
Generated in 0.06 sec. Snitz's Forums 2000