This edition of NUtrino presents the basics of calculating radioactive decay and converting counts to activity. Radiation Safety Handbook sections 9 and 10 present a more complete discussion.
Radioactive decay is a random process.
We can describe the decay of any particular atom only as a probability that it will occur within a specified interval. First, use a standard of known activity and similar quench to calculate the counter's efficiency. Circulate it among the radiation workers in your group and have them sign and date the training form on the back. File it with your authorization and other radiation safety documents for review during regulatory inspections. Discuss it during laboratory meetings.