This part of this European Standard applies only to refrigerant compressors and describes a number of selected performance test methods. These methods provide sufficiently accurate results for the determination of the refrigerating capacity, power absorbed, refrigerant mass flow, isentropic efficiency and the coefficient of performance. This standard applies only to performance tests conducted at the manufacturer's works or wherever the equipment for testing to the accuracy required is available. The type of measuring instrument and the allowable uncertainty within which measurements shall be made are listed in normative Annex A.