The GammaMaster is sensitive enough so that every day items may be used to check its response to radiation. For more information please see the our FAQ page. We also offer our customers the option of purchasing small check sources from us. These are fabricated from thoriated TIG welding electrodes (Thorium is a naturally occurring radioactive metal.)

We offer a source consisting of pieces of thoriated tungsten incased in plastic for $20.00.

We only ship sources within North America. Sources are shipped separately from the watch. Shipping and handling is included in the price. For our Canadian customers, we even pay the GST.

US and Canadian customers will be given the option of buying a check source after they have completed the check out for the GammaMaster. Please Email us if you have already purchased a GammaMaster and would like to order a check source.