1.1 The objective of this guide is to provide useful information for the interpretation of radiological instrument responses in the event of a radiological incident or emergency.1.2 For the purposes of this guide, a radiological incident or emergency is defined as those events that follow the indication of the presence of radioactive material outside of a Department of Energy (DOE) or Nuclear Regulatory Commission (NRC) defined radiological area. The event may be triggered by a law enf