Search found 1005 matches

by mightyohm
Mon Nov 04, 2019 10:11 am
Forum: Geiger Counter
Topic: the geiger poti has no effect
Replies: 1
Views: 74

Re: the geiger poti has no effect

Hi Didi, Those gas lamp mantles are not always radioactive. In fact, in the US it has become hard to find the radioactive mantles since the 1990s. It sounds like your kit is working normally. The pot does not have much effect. Adjust it to about 1/3 to 1/2 way up the dial. See if you can find some o...
by mightyohm
Tue Sep 03, 2019 12:50 pm
Forum: Geiger Counter
Topic: converting Becquerel to microsievert
Replies: 1
Views: 580

Re: converting Becquerel to microsievert

uSv is calculated using a conversion factor baked into the firmware. The conversion factor converts CPM to uSv/hr.
I don't have much additional information - the conversion factor is typically provided by the geiger tube manufacturer.
by mightyohm
Tue Sep 03, 2019 12:46 pm
Forum: HV Rescue Shield
Topic: Does it work with the ATtiny861A
Replies: 1
Views: 645

Re: Does it work with the ATtiny861A

It looks like the ATtiny861A uses a slightly different pinout for HVPP. As a result, the existing sketch won't work without modification.

Did you purchase a kit? If so, email your order details to support@mightyohm.com and let's work together on getting this working for you.
by mightyohm
Thu Aug 01, 2019 3:00 pm
Forum: Geiger Counter
Topic: Detecting Only Gamma <?>
Replies: 1
Views: 635

Re: Detecting Only Gamma <?>

Unfortunately this is not possible to do in software. You can try shielding the tube with some metal foil to decrease beta sensitivity.
by mightyohm
Thu Aug 01, 2019 2:59 pm
Forum: Geiger Counter
Topic: Position of a geiger tube
Replies: 1
Views: 686

Re: Position of a geiger tube

The orientation of the tube definitely affects the sensitivity. It should be parallel to the source to maximize sensitivity.
by mightyohm
Mon Jun 10, 2019 3:40 pm
Forum: Geiger Counter
Topic: updated software, add-on display
Replies: 2
Views: 1170

Re: updated software, add-on display

flipflip -

Wow, that display is really cool! Thanks for sharing.

I'll see if I can fix the attachment settings, sorry about that!
by mightyohm
Mon Jun 10, 2019 3:22 pm
Forum: Geiger Counter
Topic: range of geiger counter
Replies: 7
Views: 1678

Re: range of geiger counter

Again, it is very hard to say because it depends on the nature of the radiation, the difficulty of interpreting the results, and what is considered "safe". It would be very difficult to use the kit safely in an area with that level of radiation. The kit is not intended to be used for this purpose. I...
by mightyohm
Thu May 30, 2019 9:18 am
Forum: Geiger Counter
Topic: range of geiger counter
Replies: 7
Views: 1678

Re: range of geiger counter

The intensity of radiation measured at a distance from a radioactive source falls with the square of the distance from the source. This is called the inverse square law: https://www.nde-ed.org/GeneralResources/Formula/RTFormula/InverseSquare/InverseSquareLaw.htm A really powerful source will be meas...
by mightyohm
Tue May 28, 2019 8:22 pm
Forum: Geiger Counter
Topic: range of geiger counter
Replies: 7
Views: 1678

Re: range of geiger counter

That’s a difficult question to answer as it depends on the source you are trying to measure. Can you provide more details?
by mightyohm
Tue May 28, 2019 12:48 pm
Forum: Geiger Counter
Topic: range of geiger counter
Replies: 7
Views: 1678

Re: range of geiger counter

It will depend on the tube you decide to use. The datasheet for the SBM-20 is here:

https://www.gstube.com/data/2398/

It shows 0.014 - 144 mR/hr but I haven't verified this.