Scope of the Guide: "This guide is not all-inclusive of the subject of impedance measurement and the reader should understand at the outset what he can or cannot expect to find. To help in establishing the bounds of subject matter included, consider the ideal impedance-measuring instrument as having the following the characteristics and capabilities: (1) unrestricted frequency range (2) unrestricted impedance range (3) unrestricted capabilities with respect to bias, ambience, applied power, etc. (4) error free (5) performs measurements instantaneously (6) zero acquisition cost (7) zero operating cost."

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."