This part of ISO 7919 sets out general guidelines for measuring and evaluating machinery vibration by means of measurements made directly on rotating shafts for the purpose of determining shaft vibration with regard to a) changes in vibrational behaviour; b) excessive kinetic load; c) the monitoring of radial clearances. It is applicable to measurements of both absolute and relative radial shaft vibration, but excludes torsional and axial shaft vibration. The procedures are applicable for both operational monitoring of machines and to acceptance testing on a test stand and after installation. Guidelines are also presented for setting operational limits. NOTES 1 Evaluation criteria for different classes of machinery will be included in other parts of ISO 7919 when they become available. In the meantime, guidelines are given in annex A. 2 The term "shaft vibration" is used throughout ISO 7919 because, in most cases, measurements will be made on machine shafts; however, ISO 7919 is also applicable to measurements made on other rotating elements if such elements are found to be more suitable, provided that the guidelines are respected. For the purposes of ISO 7919, operational monitoring is considered to be those vibration measurements made during the normal operation of a machine. ISO 7919 permits the use of several different measurement quantities and methods, provided that they are well defined and their limitations are set out, so that the interpretation of the measurements will be well understood. This part of ISO 7919 does not apply to reciprocating machinery.