The rules given in this standard are applicable primarily to thermal acceptance tests with high accuracy for condensing steam turbines driving generators for electric power services. Some of the provisions of these rules are relevant to turbines for applications other than driving electric power generators. These rules provide for the testing of turbines operating with either superheated or saturated steam. They include measurements and procedures required to determine specific enthalpy within the moisture region and describe precautions necessary to permit testing while respecting radiological safety rules in nuclear plants. These rules contain information also applicable to the testing of back-pressure turbines, extraction turbines and mixed-pressure turbines. Only the relevant portion of the rules need apply to any individual case. Uniform rules for the preparation, carrying out and evaluation of the acceptance tests are defined in this standard. Details of the conditions under which the acceptance tests shall take place are included. Should any complex or special case arise not covered by these rules, appropriate agreement shall be reached by manufacturer and purchaser before the contract is signed.