This part of ISO 3529 defines general terms used in vacuum technology. It gives theoretical definitions as precise as possible, bearing in mind the need for use of the concept in practice. If difficulties arise in the use of these definitions in connection with measurement of some quantities, it is recommended that reference be made to the International Standards related to the measurement of those quantities for the practical interpretation of the terms. NOTES 1 In addition to terms used in the three official ISO languages (English, French and Russian), this International Standard gives the equivalent terms in the German language; these have been included at the request of Technical Committee ISO/TC 112, and are published under the responsibility of the Member Body for Germany, F.R. (DIN). However, only the terms and definitions given in the official languages can be considered as ISO terms and definitions. 2 The following abbreviations are used in connection with the French and German terms in this document : (m) masculine (f) feminine (n) neuter