TIG welding rod as radioactive source

Support forum for the mightyohm.com Geiger Counter.
http://mightyohm.com/geiger
Post Reply
teus
Posts: 3
Joined: Mon Feb 08, 2016 7:48 am

TIG welding rod as radioactive source

Post by teus »

Some TIG welding rods contain Thorium, as stated on the Mighty Ohm page with radioactive test sources
Oxides used are primarily those of zirconium, thorium, lanthanum, yttrium or cerium. Additions are usually of order 1%-4%. All these oxides greatly improve arc initiation, especially when direct current (DC) welding is employed. Thorium oxide (thoria) has been used for many years having been found effective in terms of long life and thermal efficiency. Zirconium oxide (zirconia) has been commonly used for alternating current (AC) TIG welding, normally for welding aluminium.
Oxides used are primarily those of zirconium, thorium, lanthanum, yttrium or cerium. Additions are usually of order 1%-4%. All these oxides greatly improve arc initiation, especially when direct current (DC) welding is employed. Thorium oxide (thoria) has been used for many years having been found effective in terms of long life and thermal efficiency. Zirconium oxide (zirconia) has been commonly used for alternating current (AC) TIG welding, normally for welding aluminium.
I went to a welding shop. They say thoriated welding rods aren't supposed to be sold anymore, but they managed to find me a stick in their workshop. A red ring marks a thorium content of 2%, a yellow ring marks a 1% content.
And yup, it works well to test:

https://www.youtube.com/watch?v=DmLcmQ5A-vY
User avatar
mightyohm
Site Admin
Posts: 1064
Joined: Fri Apr 03, 2009 10:29 pm
Location: Seattle, WA
Contact:

Re: TIG welding rod as radioactive source

Post by mightyohm »

did you change the frequency of the beep? it sounds like your MCU might not be running at full speed (check the CLKDIV fuse bytes)
Post Reply