This page presents many questions asked by site users with their responses. Please search this page for answers to your questions prior to contacting technical support staff. Researching the questions and answers posted here will greatly reduce the time it takes for you to solve many problems that arise from calculating and using this CPM site.

1. How does the CPM Calculator address daughter ingrowth?
2. What assumptions does the CPM Calculator make?
3. Why doesn't the CPM Calculator address alpha and beta emitters?
4. Where can I find more information about radionuclide decay chains?

1. How does the CPM Calculator address daughter ingrowth?

   On the calculator main page, the user has the option to include progeny contribution. If selected, a normalized and weighted detector energy response is used to correct the detector response to account for the photon energy spectrum of the chain.

2. What assumptions does the CPM Calculator make?

   The CPM Calculator model makes several simplifying assumptions that are not likely to exist in the field. It assumes the surface is infinite in area, flat, and free from shielding by grass, oil, or water and that the media is uniformly contaminated such that the radionuclides are in a constant ratio to each other. Altering any of these assumptions may contribute to inaccurate results of the CPM Calculator.

3. Why doesn't the CPM Calculator address alpha and beta emitters?

   Nuclides that emit alpha and beta radiation are difficult to measure with any accuracy in the field and are omitted from this model, unless the radionuclide also emits a qualifying gamma particle.

4. Where can I find more information about radionuclide decay chains?

   Decay chain information can be found by using the Radionuclide Decay Chain Tool