From Introduction: "The purpose of this guide is to describe, discuss, and analyze methods of measuring the average noise factor and average effective input noise temperature of an electronic transducer."

Report issued by the U.S. Bureau of Mines discussing the Flathead Tunnel in Montana. As stated in the introduction, "this information circular is a Bureau of Mines review of tunneling practices typical of the late 1960's. The report provides reference to all pertinent data related to the geology, mining operations, and ground support practices for the Flathead Tunnel" (p. 2). This report includes maps, tables, illustrations, and photographs.

From Abstract: "This is a tutorial Monograph describing various aspects of time and frequency (T/F). Included are chapters relating to elemental concepts of precise time and frequency; basic principles of quartz oscillators and atomic frequency standards; historical review, recent progress, and current status of atomic frequency standards; promising areas for developing future primary frequency standards; relevance of frequency standards to other areas of metrology including a unified standard concept; statistics of T/F data analysis coupled with the theory and construction of the NBS atomic time scale; an overview of T/F dissemination techniques; and the standards of T/F in the USA. The Monograph addresses both the specialist in the field as well as those desiring basic information about time and frequency."