How is well counter efficiency calculated?

The calculation of well counter efficiency is determined by the ratio of the counts detected by the well counter, expressed in counts per minute (CPM), to the actual disintegrations occurring in the sample, expressed in disintegrations per minute (DPM). Thus, to find the efficiency, which is a measure of how effectively the counter detects the disintegrations, you divide the measured counts (CPM) by the true disintegrations (DPM) and then multiply by 100 to convert it into a percentage.

This method provides a clear understanding of how effectively the well counter operates in measuring radioactive emissions. A higher efficiency percentage indicates a more reliable and effective counter. Therefore, the formula CPM/DPM x 100 aligns directly with this principle, allowing for an easy comparison between the measured count and the actual activity of the sample.