ABSTRACT
International Atomic Energy Agency (IAEA) disseminates the unit to the national SSDLs which in turn offer calibration to the regional calibration laboratories, or directly to the local users. There are two basic methods followed for the calibration of the protection instruments: source in open air geometry and a collimated beam facility. The source output roughly follows an inverse square law. Thus by measuring the output, in units of absorbed dose equivalent (ADE) or absorbed dose equivalent rate (ADER), at one distance, the output at other distances can be computed. To characterize the photon fields in terms of air kerma (AK) and air kerma rate (AKR), the AK or the AKR must be actually measured using a reference standard, in the calibration field. A more accurate method of fluence standardization of the neutron field is by actually measuring the neutron fluence using the reference standard of neutron fluence, the PLC, or De Pangher long counter.
