The instruments and methods required for radioactivity determination depend on the types of nuclides and rays.
For example: 3H, 14C, 32P, etc. Can be measured by liquid scintillation counter (liquid scintillation);
125I, 60Co, etc. γ counter (or radioimmunoassay) can be used for rapid determination;
For nuclides that emit gamma rays, it is certainly better to measure them with a gamma spectrometer.
In order to prevent pollution, there are surface pollution detectors.
In a word, there are many instruments involved in radioactive detection, and appropriate detection instruments and methods should be determined according to specific conditions.