This standard specifies the operational and performance requirements for spectroscopy-based portal monitors (SRPMs) used in homeland security applications. SRPMs have the ability to detect radioactivity and identify radionuclides that may be present in or on persons, vehicles, or containers through the use of gamma spectroscopy techniques. Operational requirements established by this standard include radiation detection and radionuclide identification, and those requirements associated with the expected electrical, mechanical, and environmental conditions when a SRPM is deployed. The test methods described in this standard provide a means to ensure that a SRPM meets the requirements stated. Successful completion of the tests described in this standard should not be construed as an ability to successfully detect and identify all radionuclides in all environments. This standard does not address portal monitors that may have the ability to reduce the effects caused by the presence of naturally occurring radioactive material (NORM) without the ability to identify specific radionuclides. Monitors with this capability are addressed by ANSI N42.35.