The ORTEC Detective-EX®-100T portable nuclide identifier uses both a high-purity germanium (HPGe) detector for identification using gamma-ray emissions and a moderated neutron detector for detection of the neutron emissions. The Detective-DX-100T is identical to the -EX-100T but has no neutron detector.1 The HPGe detector is cooled by a miniature, high-reliability mechanical cooler — no liquid nitrogen is required. The user interface is a high-resolution color touchscreen. The result is a lightweight and rugged instrument that delivers unmatched identification and detection for the needs of nuclear security. The Detective-EX identifies and classifies radionuclides according to the requirements of ANSI N42.34 and other standards. The radionuclide library for this release of the Detective-EX is detailed in Chapter 4.2 The Detective-EX can make an accurate and fast determination without the need for expert human intervention. Nuclide identifications are based on the gamma-ray peaks in the spectrum and on other aspects of the total spectrum.