The 240-page 2nd Edition of this popular treatise, first published in 2005, captures the thought process behind the evolution of MIL-STD-810, Test Method Standard for Environmental Engineering Considerations and Laboratory Test. The new edition includes background and analysis to assist in the interpretation of the latest revision of the standard, MIL-STD-810G, published in October 2008. Author Herbert W. Egbert, a Fellow of IEST, was heavily involved in the development of revisions 810D through 810G. The History and Rationale provides a development history of test methods, rationale for many procedural changes, tailoring guidance for many test procedures, and insight into the future direction of the standard. The document also provides a practical reference for those wishing to submit comments concerning future editions of the Standard