In a typical system, a number of samples are placed in sealed vials or test tubes, and moved along a track.
One at a time, they move down inside a shielded detector, set to measure specific energy windows characteristic of the particular isotope.
[1][2] Depending on the half-life and concentration of the sample, measurement times may vary from 0.02 minutes to several hours.
[3][4] Gamma counters are standard tools used in the research and development of new radioactive compounds used for diagnosing (and treating disease) as in PET scanning.
Gamma counters are used in radiobinding assays,[5] radioimmunoassays (RIA)[6] and nuclear medicine measurements such as GFR[7] and hematocrit.