gamma counter       
noun [ C ] uk/ˈɡæm.ə ˌkaʊn.tər/ us/ˈɡæm.ə ˌkaʊn.t̬ɚ/
 伽玛计数器
an electronic device that can measure the level of gamma radiation (= a type of radiation with a very short wavelength that passes through most solid objects) in a small amount of material
  Tissue was removed and placed in a gamma counter to assess its radioactive content.  组织被移除并放置在伽玛计数器中,以评估其放射性含量。 
 Compare: gamma meter
 - More examples
 - Tumor samples were obtained during cystoscopy and were counted in a gamma counter.
 - Gamma counters are standard tools used in the development of new radioactive compounds for diagnosing and treating disease (as in PET scanning).