MIL-HDBK-235-1C (1 October 2010) superseding MIL-HDBK-235-1B (19 May 1993). DoD activities have experienced increasingly serious problems of damage and performance degradation to electrical and electronic equipment, subsystems, and systems due to inadequate consideration of the intended operational electromagnetic environment in their initial design. To correct this, general design requirements and limits in existing electromagnetic compatibility (EMC) and interference (EMI) standards must be analyzed to determine their suitability and applicability for a given development and procurement. The standards are to be tailored by the procuring activity to the peculiarities of the specific equipment, its mission and operational concepts, the probabilities of achieving intra- and inter-system EMC, program cost objectives and anticipated operational electromagnetic environment. Definitive postulations of the total intended environment are required at various stages during the system design, as well as requirements to demonstrate operation and survivability in those environments. An initial postulation of the environment should be included in the specification. This postulation may be based on the assumption that the emitters with the largest radiated levels represent the greatest threat. From this, the extreme EM environment parameters which can be encountered during the system's life cycle may be documented. Subsequent analyses may show that the initial assumptions yielded extremely high environment levels thus necessitating revisions of the initially postulated environment. The revised environment levels could then be used by the designer or testing organization.
This document provides information and guidance to the project manager, acquisition manager and others responsible for the design, test and procurement of electrical and electronic components, equipment, subsystems and systems on the representative maximum electronic environment which may be encountered at various stages of their life cycle. The intent of this document is not to provide detailed EM specifications since each equipment and procurement is somewhat unique, but rather, to provide guidance and information which must be weighed during design and procurement. Use of this document will require engineering judgement. Therefore, it is advisable to search out the additional EM environment data in the referenced publications when more precise or detailed environmental information is required.
