This code may be used for testing of steam turbines operating either with a significant amount of superheat in the initial steam (typically fossil fueled units) or predominantly within the moisture region (typically nuclear fueled units). This code contains rules and procedures for the conduct and reporting of steam turbine testing, including mandatory requirements for pretest arrangements, instruments to be employed, their application and methods of measurement, testing techniques, and methods of calculation of test results. The performance parameters which may be determined from a Code test include: (a) heat rate, (b) generator output, (c) steam flow, (d) steam rate, (e) feedwater flow. It also contains procedures and techniques required to determine enthalpy valves within the moisture region and modifications necessary to permit testing within the restrictions of radiological safety requirements in nuclear plants.