The Technical Committee for Ionising Radiation (TC-IR) is concerned with the metrology of ionising radiation related to medical, industrial, environmental, scientific and radiation protection applications. According to the type and nature of ionising particles and quantities required to measure, radiation dosimetry and radionuclide-/neutron measurements are the main subfields. 
 
The fundamental SI quantities and units are the

• Particle Fluence, Ф (m^-2)
• Activity, (s^-1) special name is becquerel (Bq)
• Kerma , K, (J/kg) special name is gray (Gy)
• Absorbed Dose , D, (J/kg) special name is gray (Gy)
• Dose Equivalent, H, (J/kg) special name is sievert (Sv)