This European Standard specifies the rating conditions, tolerances and the method of presenting manufacturer' s data for positive displacement refrigerant compressors. These include single stage compressors and single and two stage compressors using a means of liquid subcooling. This is required so that a comparison of different refrig-erant compressors can be made. The data related to the refrigerating capacity and power absorbed, include correc-tion factors and part-load performance where applicable.