{"id":4772,"date":"2012-02-14T09:52:57","date_gmt":"2012-02-14T15:52:57","guid":{"rendered":"http:\/\/mightyohm.com\/blog\/?p=4772"},"modified":"2022-12-27T17:39:07","modified_gmt":"2022-12-28T01:39:07","slug":"feed-your-geiger-readily-available-radioactive-test-sources","status":"publish","type":"post","link":"https:\/\/mightyohm.com\/blog\/2012\/02\/feed-your-geiger-readily-available-radioactive-test-sources\/","title":{"rendered":"Feed your Geiger: Cheap and Readily Available Radioactive Test Sources"},"content":{"rendered":"<p>Want to check if your freshly-assembled <a href=\"http:\/\/mightyohm.com\/geiger\">MightyOhm Geiger Counter kit<\/a> is working? You&#8217;ll need something radioactive! But why pay over $100 for a professional test source when there are plenty of cheap and readily available radioactive items available at your local antique store or online?<\/p>\n<p><!--more--><\/p>\n<p>The disadvantage of using these sources is that you won&#8217;t be able to calibrate your geiger counter, but for simple go\/no-go testing (which is what most people need) these are perfect!<\/p>\n<p>Here are a few of my favorites:<\/p>\n<h2>Readily Available Radioactive Test Sources<\/h2>\n<h3>Granite tables and countertops<\/h3>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/30621297@N08\/2868751716\/\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"4814\" data-permalink=\"https:\/\/mightyohm.com\/blog\/2012\/02\/feed-your-geiger-readily-available-radioactive-test-sources\/2868751716_64c64d07c7\/\" data-orig-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/2868751716_64c64d07c7.jpg\" data-orig-size=\"348,500\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"Cooking Area\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/2868751716_64c64d07c7.jpg\" class=\"alignnone size-full wp-image-4814\" title=\"Cooking Area\" src=\"http:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/2868751716_64c64d07c7.jpg\" alt=\"\" width=\"348\" height=\"500\" \/><\/a><br \/>\n(photo credit: <a href=\"http:\/\/www.flickr.com\/photos\/30621297@N08\/\">Hidesert<\/a>)<\/p>\n<p><a href=\"http:\/\/en.wikipedia.org\/wiki\/Granite\">Granite<\/a> often <a href=\"http:\/\/en.wikipedia.org\/wiki\/Granite#Natural_radiation\">contains traces of Uranium<\/a>, which makes it slightly radioactive. Because granite is commonly used in structural and ornamental building materials, it is easy to find and may already be present in your home (check your kitchen countertops!)<\/p>\n<p><strong>CPM:<\/strong> varies<br \/>\n<strong>Sources:<\/strong> Your newly-remodeled kitchen, <a href=\"http:\/\/www.homedepot.com\">Home Depot<\/a>, public spaces, stores that sell building materials, in the ground<br \/>\n<strong>Cost:<\/strong> $0<\/p>\n<h3>Uranium glass<\/h3>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/mightyohm\/6167948098\/\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"4815\" data-permalink=\"https:\/\/mightyohm.com\/blog\/2012\/02\/feed-your-geiger-readily-available-radioactive-test-sources\/ooh-pretty\/\" data-orig-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6167948098_581ddf3d7d.jpg\" data-orig-size=\"500,375\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;Jeff Keyzer&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;Vaseline glass marbles under UV light.&quot;,&quot;created_timestamp&quot;:&quot;1316341897&quot;,&quot;copyright&quot;:&quot;Jeff Keyzer&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;Ooh, pretty.&quot;}\" data-image-title=\"Uranium glass marbles\" data-image-description=\"&lt;p&gt;Vaseline glass marbles under UV light.&lt;\/p&gt;\n\" data-image-caption=\"\" data-large-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6167948098_581ddf3d7d.jpg\" class=\"alignnone size-full wp-image-4815\" title=\"Uranium glass marbles\" src=\"http:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6167948098_581ddf3d7d.jpg\" alt=\"\" width=\"500\" height=\"375\" \/><\/a><br \/>\nOften called <a href=\"http:\/\/en.wikipedia.org\/wiki\/Uranium_glass#Vaseline_glass\">vaseline glass<\/a> or <a href=\"http:\/\/en.wikipedia.org\/wiki\/Depression_glass\">depression glass<\/a>, <a href=\"http:\/\/en.wikipedia.org\/wiki\/Uranium_glass\">uranium glass<\/a> contains a small amount of uranium, which makes it slightly radioactive. It also fluoresces brilliantly under UV light! Uranium glass is commonly found in depression-era glassware, the glass-to-metal seals in some old vacuum tubes, and most commonly <a href=\"http:\/\/www.ebay.com\/sch\/i.html?_nkw=vaseline+marbles\">in the form of green glass marbles on eBay<\/a>.<\/p>\n<p><strong>CPM:<\/strong> 200 for ten 1\/2&#8243; marbles placed on top of kit<br \/>\n<strong>Sources:<\/strong> <a href=\"http:\/\/www.ebay.com\/sch\/i.html?_nkw=vaseline+marbles\">eBay<\/a>, your great-grandmother&#8217;s china cabinet<br \/>\n<strong>Cost:<\/strong> $5 &#8211; $10<\/p>\n<h3>Fiesta-ware<\/h3>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/mr_physics\/4479617505\/\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"4816\" data-permalink=\"https:\/\/mightyohm.com\/blog\/2012\/02\/feed-your-geiger-readily-available-radioactive-test-sources\/4479617505_ec61413174\/\" data-orig-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/4479617505_ec61413174.jpg\" data-orig-size=\"500,332\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"Fiestaware\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/4479617505_ec61413174.jpg\" class=\"alignnone size-full wp-image-4816\" title=\"Fiestaware\" src=\"http:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/4479617505_ec61413174.jpg\" alt=\"\" width=\"500\" height=\"332\" \/><\/a><br \/>\n(photo credit: <a href=\"http:\/\/www.flickr.com\/photos\/mr_physics\/\">Mr. Physics<\/a>)<\/p>\n<p><a href=\"http:\/\/en.wikipedia.org\/wiki\/Fiestaware\">Fiesta-ware<\/a> produced before 1969(?) is often radioactive, thanks to <a href=\"http:\/\/en.wikipedia.org\/wiki\/Fiestaware#Radioactive_Glazes\">a glaze that contains uranium oxide<\/a>. Bright orange\/red (often called Radioactive Red) pieces are surprisingly potent, but other colors may be radioactive as well. <a href=\"http:\/\/www.ebay.com\/sch\/i.html?_nkw=fiestaware+radioactive\">Fiesta-ware is readily available on eBay<\/a>, but radioactive dinnerware can be found in many homes. (A friend of mine was shocked to discover that half of the place-settings used for Thanksgiving dinner at his grandmother&#8217;s house were quite radioactive.)<\/p>\n<p>According to <a href=\"http:\/\/www.orau.org\/ptp\/collection\/consumer%20products\/fiesta.htm\">this study<\/a> by the <a href=\"http:\/\/www.orau.org\/\">Oak Ridge Associated Universities<\/a>, accidental uranium ingestion resulting from using all Fiesta-ware dinnerware every day was &#8220;the highest dose calculated in any of the exposure pathways considered&#8230;&#8221; The glaze used on these plates also contains lead, so I highly recommend using Fiesta-ware to show off your gieger counter, not at the dinner table!<\/p>\n<p>Orange or red Fiesta-ware that is sold today is not radioactive. It is my understanding that uranium oxide hasn&#8217;t been used in dinnerware much since the 1970s. Note that the use of uranium oxide was not restricted to Fiesta-ware, it was also widely used in the manufacturing of ornamental ceramics such as <a href=\"http:\/\/www.orau.org\/ptp\/collection\/consumer%20products\/greentile.htm\">bathroom tiles<\/a>.<\/p>\n<p><strong>Fun fact: <\/strong>Red Fiesta-ware was discontinued during WWII after the US government <a href=\"http:\/\/www.orau.org\/ptp\/collection\/consumer%20products\/fiesta.htm\">seized the company&#8217;s stocks of uranium<\/a>.<\/p>\n<p><strong>CPM:<\/strong> over 6000 for a 6&#8243; dessert plate<br \/>\n<strong>Sources:<\/strong> <a href=\"http:\/\/www.ebay.com\/sch\/i.html?_nkw=fiestaware+radioactive\">eBay<\/a>, antique shops, your grandmother&#8217;s house<br \/>\n<strong>Cost:<\/strong> $15 &#8211; $30 (and up)<\/p>\n<h3>Luminous watches and instrument dials<\/h3>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/radioactiverosca\/6862170947\/\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"4817\" data-permalink=\"https:\/\/mightyohm.com\/blog\/2012\/02\/feed-your-geiger-readily-available-radioactive-test-sources\/6862170947_71cc5bc780\/\" data-orig-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6862170947_71cc5bc780.jpg\" data-orig-size=\"500,333\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"Clock with Radium paint\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6862170947_71cc5bc780.jpg\" class=\"alignnone size-full wp-image-4817\" title=\"Clock with Radium paint\" src=\"http:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6862170947_71cc5bc780.jpg\" alt=\"\" width=\"500\" height=\"333\" \/><\/a><br \/>\n(photo credit: <a href=\"http:\/\/www.flickr.com\/photos\/radioactiverosca\/\">Radioactive Rosca<\/a>)<\/p>\n<p>Vintage watches and aircraft dials may contain <a href=\"http:\/\/en.wikipedia.org\/wiki\/Radium\">radium<\/a>, which was used to make them glow in the dark. Radium is <a href=\"http:\/\/en.wikipedia.org\/wiki\/Radium#Radioactivity\">over one million times more radioactive than Uranium<\/a>, emits all kinds of radiation (alpha, beta, and gamma), and should be handled with care. Nonetheless, radium dial watches are fairly common in antique shops and I have seen radium dials on aircraft gauges in surplus stores. Note that the paint will stop glowing long before the dial stops being radioactive (radium has a half life of 1600 years), so bring a geiger counter.<\/p>\n<p><strong>Note:<\/strong> To my knowledge, radium is (thankfully) no longer used to make glow in the dark watches. It has been replaced by Tritium gas (which is <del datetime=\"2017-06-10T17:41:13+00:00\">an alpha-emitter but the alpha radiation is blocked by the walls of the vial containing it<\/del> a beta source) or more commonly <a href=\"http:\/\/en.wikipedia.org\/wiki\/Zinc_sulfide\">zinc sulfide<\/a>.<\/p>\n<p><strong>CPM:<\/strong> over 10,000 for a small aircraft gauge<br \/>\n<strong>Sources:<\/strong> <a href=\"http:\/\/www.ebay.com\/sch\/i.html?_nkw=radium+dial\">eBay<\/a>, antique stores, military and electronics surplus stores<br \/>\n<strong>Cost:<\/strong> $5 &#8211; $10 for surplus gauges, watches are $20 and up<\/p>\n<h3>Uraninite and other radioactive ore samples<\/h3>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/radioactiverosca\/6862869951\/\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"4818\" data-permalink=\"https:\/\/mightyohm.com\/blog\/2012\/02\/feed-your-geiger-readily-available-radioactive-test-sources\/6862869951_0b20ca4656\/\" data-orig-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6862869951_0b20ca4656.jpg\" data-orig-size=\"500,333\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"Pitchblende\/Uraninite Uranium Oxide Mineral Ore\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6862869951_0b20ca4656.jpg\" class=\"alignnone size-full wp-image-4818\" title=\"Pitchblende\/Uraninite Uranium Oxide Mineral Ore\" src=\"http:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6862869951_0b20ca4656.jpg\" alt=\"\" width=\"500\" height=\"333\" \/><\/a><br \/>\n(photo credit: <a href=\"http:\/\/www.flickr.com\/photos\/radioactiverosca\/\">Radioactive Rosca<\/a>)<\/p>\n<p>Uranium ore (<a href=\"http:\/\/en.wikipedia.org\/wiki\/Uraninite\">uraninite<\/a> or pitchblende) is commonly available on eBay and from United Nuclear.<\/p>\n<p><strong>CPM:<\/strong> sometimes specified with the sample<br \/>\n<strong>Sources:<\/strong> <a href=\"http:\/\/www.ebay.com\/sch\/i.html?_nkw=uranium+ore\">eBay<\/a>, <a href=\"http:\/\/unitednuclear.com\/index.php?main_page=index&amp;cPath=2_4\">United Nuclear<\/a>, strewn across New Mexico<br \/>\n<strong>Cost:<\/strong> $10 &#8211; $20<\/p>\n<h3>Lantern mantles<\/h3>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/mightyohm\/6871472153\/in\/photostream\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"4819\" data-permalink=\"https:\/\/mightyohm.com\/blog\/2012\/02\/feed-your-geiger-readily-available-radioactive-test-sources\/6871472153_0d5dab35cf\/\" data-orig-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6871472153_0d5dab35cf.jpg\" data-orig-size=\"386,500\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"Coleman Silk Like Mantles\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6871472153_0d5dab35cf.jpg\" class=\"alignnone size-full wp-image-4819\" title=\"Coleman Silk Like Mantles\" src=\"http:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6871472153_0d5dab35cf.jpg\" alt=\"\" width=\"386\" height=\"500\" \/><\/a><\/p>\n<p>Camping lantern mantles manufactured before the 1990s <a href=\"http:\/\/www.orau.org\/ptp\/collection\/consumer%20products\/mantle.htm\">are likely to contain thorium<\/a>, which makes them burn more brightly.<\/p>\n<p><strong>Note: <\/strong>Most lantern mantles sold at camping goods stores today contain Yttrium instead of thorium. They are (sadly) not radioactive.<\/p>\n<p><strong>CPM:<\/strong> 3500 for a package of 2 mantles (as shown)<br \/>\n<strong>Sources:<\/strong> <a href=\"http:\/\/www.ebay.com\/sch\/i.html?_nkw=radioactive+mantle\">eBay<\/a>, antique stores, camping supply stores with dusty shelves<br \/>\n<strong>Cost:<\/strong> $2 &#8211; $10<\/p>\n<h3>Thoriated optics<\/h3>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/s58y\/5770714676\/\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"4820\" data-permalink=\"https:\/\/mightyohm.com\/blog\/2012\/02\/feed-your-geiger-readily-available-radioactive-test-sources\/5770714676_70e135eb4e\/\" data-orig-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/5770714676_70e135eb4e.jpg\" data-orig-size=\"485,500\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"Canon FD 55mm f\/1.2 S.S.C. Aspherical Lens (radioactive)\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/5770714676_70e135eb4e.jpg\" class=\"alignnone size-full wp-image-4820\" title=\"Canon FD 55mm f\/1.2 S.S.C. Aspherical Lens (radioactive)\" src=\"http:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/5770714676_70e135eb4e.jpg\" alt=\"\" width=\"485\" height=\"500\" \/><\/a><\/p>\n<p>Some 1970s-vintage camera lenses <a href=\"http:\/\/www.orau.org\/ptp\/collection\/consumer%20products\/cameralens.htm\">contain thorium<\/a>, which is used to increase the index of refraction in glass. These are probably rare, but you just might stumble upon a Thoriated lens in an antique shop or surplus store, so I thought I would mention them here.<\/p>\n<p><strong>CPM:<\/strong> unknown<br \/>\n<strong>Source:<\/strong> Antique stores, camera shops, hipsters&#8217; camera bags, your basement<br \/>\n<strong>Cost:<\/strong>???<\/p>\n<h3>TIG welding rods<\/h3>\n<p>Some TIG welding rods are radioactive because they <a href=\"http:\/\/www.orau.org\/ptp\/collection\/consumer%20products\/weldingrod.htm\">contain thorium<\/a>.<\/p>\n<p><strong>CPM:<\/strong> unknown<br \/>\n<strong>Sources:<\/strong> Welding supply shops, <a href=\"http:\/\/www.ebay.com\/sch\/i.html?_nkw=tig+thoriated\">eBay<\/a><br \/>\n<strong>Cost:<\/strong> $5 &#8211; $10<\/p>\n<h2>Things that are not good test sources:<\/h2>\n<p>Here are a few examples of items that are <strong>not<\/strong> good test sources, at least not for the <a href=\"http:\/\/mightyohm.com\/geiger\">MightyOhm Geiger Counter kit<\/a>:<\/p>\n<h3>Household smoke detectors<\/h3>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/mag3737\/345145225\/\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"4821\" data-permalink=\"https:\/\/mightyohm.com\/blog\/2012\/02\/feed-your-geiger-readily-available-radioactive-test-sources\/345145225_1ca8df358a\/\" data-orig-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/345145225_1ca8df358a.jpg\" data-orig-size=\"500,500\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"Smoke alarm\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/345145225_1ca8df358a.jpg\" class=\"alignnone size-full wp-image-4821\" title=\"Smoke alarm\" src=\"http:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/345145225_1ca8df358a.jpg\" alt=\"\" width=\"500\" height=\"500\" srcset=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/345145225_1ca8df358a.jpg 500w, https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/345145225_1ca8df358a-150x150.jpg 150w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/a><br \/>\n(photo credit: <a href=\"http:\/\/www.flickr.com\/photos\/mag3737\/\">mag3737<\/a>)<\/p>\n<p>Not all household smoke detectors are radioactive, but even the ones that are radioactive are not good test sources for my geiger counter kit.<\/p>\n<p>Why? Because smoke detectors use <a href=\"http:\/\/en.wikipedia.org\/wiki\/Americium\">Americium<\/a>, a powerful alpha emitter.<\/p>\n<p>Not only is Americium dangerous to handle (ingestion of alpha-emitters can be very harmful), but the SBM-20 tube used in my geiger counter kit isn&#8217;t sensitive to alpha radiation, so you&#8217;ll only get a faint and very disappointing reading from the beta\/gamma radiation emitted by Americium&#8217;s decay products.<\/p>\n<h3>Bananas<\/h3>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/pykmi\/2215231878\/\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"4822\" data-permalink=\"https:\/\/mightyohm.com\/blog\/2012\/02\/feed-your-geiger-readily-available-radioactive-test-sources\/2215231878_92db12718e\/\" data-orig-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/2215231878_92db12718e.jpg\" data-orig-size=\"500,333\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"Bananas!\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/2215231878_92db12718e.jpg\" class=\"alignnone size-full wp-image-4822\" title=\"Bananas!\" src=\"http:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/2215231878_92db12718e.jpg\" alt=\"\" width=\"500\" height=\"333\" \/><\/a><br \/>\n(photo credit: <a href=\"http:\/\/www.flickr.com\/photos\/pykmi\/\">pykmi<\/a>)<\/p>\n<p>Bananas, which are indeed <a href=\"http:\/\/en.wikipedia.org\/wiki\/Banana_equivalent_dose\">slightly radioactive<\/a> because they contain trace amounts of <a href=\"http:\/\/en.wikipedia.org\/wiki\/Potassium-40\">Potassium-40<\/a>, are not a strong enough beta source to use with my geiger counter kit. (This is good news for people who eat bananas.)<\/p>\n<p><strong>Fun fact:<\/strong> <a href=\"http:\/\/www.ead.anl.gov\/pub\/doc\/potassium.pdf\">People are radioactive too!<\/a><\/p>\n<h3>Have fun!<\/h3>\n<p>That&#8217;s all for now! The <a href=\"http:\/\/www.orau.org\/\">Oak Ridge Associated Universities<\/a> website includes <a href=\"http:\/\/www.orau.org\/ptp\/collection\/consumer%20products\/consumer.htm\">an interesting page that lists several other radioactive consumer products<\/a>.<\/p>\n<p>Have fun feeding your <a href=\"http:\/\/mightyohm.com\/geiger\">MightyOhm Geiger Counter kit<\/a>, and most importantly, be safe!<\/p>\n<p>Do you have any more suggestions for readily-available radioactive test sources? Leave a comment below!<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Want to check if your freshly-assembled MightyOhm Geiger Counter kit is working? You&#8217;ll need something radioactive! But why pay over $100 for a professional test source when there are plenty of cheap and readily available radioactive items available at your local antique store or online?<\/p>\n","protected":false},"author":2,"featured_media":4815,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[65],"tags":[434,401,403],"class_list":["post-4772","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-kits","tag-ebay","tag-geiger","tag-radioactivity"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2012\/02\/6167948098_581ddf3d7d.jpg","jetpack_shortlink":"https:\/\/wp.me\/pioCd-1eY","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":9494,"url":"https:\/\/mightyohm.com\/blog\/2018\/01\/schrodingers-martini-geiger-counter-as-mixologist\/","url_meta":{"origin":4772,"position":0},"title":"Schr\u00f6dinger&#8217;s Martini: Geiger Counter as mixologist","author":"Jeff","date":"January 29, 2018","format":false,"excerpt":"Josh Meyer\u00a0and Jonathan Foote created this scintillating cocktail robot for Barbot 2013. They also exhibited it at the DNA Lounge Cocktail Robotics Grand Challenge last July. A MightyOhm Geiger Counter samples radioactive decay from a martini glass that contains a small amount of uranium. If the number of clicks in\u2026","rel":"","context":"In &quot;Kits&quot;","block_context":{"text":"Kits","link":"https:\/\/mightyohm.com\/blog\/category\/kits\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2018\/01\/schroedingers-martini-500x375.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":4258,"url":"https:\/\/mightyohm.com\/blog\/2011\/10\/geiger-counter-kits-now-for-sale-in-the-maker-shed\/","url_meta":{"origin":4772,"position":1},"title":"Geiger Counter Kits are now for sale in the Maker Shed","author":"Jeff","date":"October 14, 2011","format":false,"excerpt":"I'm pleased to announce that Geiger Counter Kits are now for sale in the Maker Shed! In this video, Make's Michael Castor shows how he used the kit to find several radioactive objects around his home. Check it out! http:\/\/www.youtube.com\/watch?v=bsnkg45s5ag Resellers: If you are interested in carrying my Geiger Counter\u2026","rel":"","context":"In &quot;Announcements&quot;","block_context":{"text":"Announcements","link":"https:\/\/mightyohm.com\/blog\/category\/announcements\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2011\/10\/MKMO1-2.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":5489,"url":"https:\/\/mightyohm.com\/blog\/2013\/05\/come-see-my-glowy-geiger-chimes-at-the-2013-maker-faire-bay-area\/","url_meta":{"origin":4772,"position":2},"title":"Come see my Glowy Geiger Chimes at the 2013 Maker Faire Bay Area!","author":"Jeff","date":"May 12, 2013","format":false,"excerpt":"It's that time of the year again! The 2013 Maker Faire Bay Area is next weekend (May 18-19th) in San Mateo, California. I haven't had time to post about it, but over the past few weeks I've been busy working on a special project for the Maker Faire this year.\u2026","rel":"","context":"In &quot;Events&quot;","block_context":{"text":"Events","link":"https:\/\/mightyohm.com\/blog\/category\/events\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":5116,"url":"https:\/\/mightyohm.com\/blog\/2012\/04\/geiger-bot-on-the-ipad\/","url_meta":{"origin":4772,"position":3},"title":"Geiger Bot on the iPad","author":"Jeff","date":"April 5, 2012","format":false,"excerpt":"Last week I went to my local Apple store and came home with a shiny new iPad. Why? So I could play with Geiger Bot for the iPad, of course!* http:\/\/www.flickr.com\/photos\/mightyohm\/6902445590\/in\/photostream Fortunately that's not the background level in my lab, but a measurement of a Fiestaware plate I have in\u2026","rel":"","context":"In &quot;Kits&quot;","block_context":{"text":"Kits","link":"https:\/\/mightyohm.com\/blog\/category\/kits\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":4135,"url":"https:\/\/mightyohm.com\/blog\/2011\/08\/radioactive-gauges-at-chaos-camp\/","url_meta":{"origin":4772,"position":4},"title":"Radioactive Gauges at Chaos Camp","author":"Jeff","date":"August 10, 2011","format":false,"excerpt":"Sorry for the poor quality of the video - this is a camp, after all.","rel":"","context":"In &quot;Electronics&quot;","block_context":{"text":"Electronics","link":"https:\/\/mightyohm.com\/blog\/category\/electronics\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":5221,"url":"https:\/\/mightyohm.com\/blog\/2012\/05\/pics-video-of-my-geiger-counter-powered-ambient-music-demo-maker-faire\/","url_meta":{"origin":4772,"position":5},"title":"Pics &#038; video of my Geiger counter powered ambient music demo @ Maker Faire","author":"Jeff","date":"May 24, 2012","format":false,"excerpt":"http:\/\/www.flickr.com\/photos\/apg88\/7245465932\/in\/faves-mightyohm\/ (photo credit: alvaroprieto) This year I decided (in true last-minute fashion) to build a couple demos to show off my Geiger Counter kit at the Maker Faire Bay Area. One of these demos used my Geiger Counter kit to create ambient music: (Thanks to @j_jwalrus for the interview and\u2026","rel":"","context":"In &quot;Electronics&quot;","block_context":{"text":"Electronics","link":"https:\/\/mightyohm.com\/blog\/category\/electronics\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/img.youtube.com\/vi\/Q_3SVE0CQqw\/0.jpg?resize=350%2C200","width":350,"height":200},"classes":[]}],"_links":{"self":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts\/4772","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/comments?post=4772"}],"version-history":[{"count":76,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts\/4772\/revisions"}],"predecessor-version":[{"id":8988,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts\/4772\/revisions\/8988"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/media\/4815"}],"wp:attachment":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/media?parent=4772"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/categories?post=4772"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/tags?post=4772"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}