NBN ISO 20816-1:2021

This document establishes general conditions and procedures for the measurement and evaluation of
vibration using measurements made on rotating, non-rotating and non-reciprocating parts of complete
machines. It is applicable to measurements of both absolute and relative radial shaft vibration with
regard to the monitoring of radial clearances, but excludes axial shaft vibration. The general evaluation
criteria, which are presented in terms of both vibration magnitude and change of vibration, relate to
both operational monitoring and acceptance testing. They have been provided primarily with regard
to securing reliable, safe, long-term operation of the machine while minimizing adverse effects on
associated equipment. Guidelines are also presented for setting operational limits.
NOTE 1 The evaluation criteria for different classes of machinery will be included in other parts of ISO 20816
when they become available. In the meantime, guidelines are given in Clause 6.
NOTE 2 The term “shaft vibration” is used throughout ISO 20816 because, in most cases, measurements
are made on machine shafts. However, the ISO 20816 series 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 20816, operational monitoring is considered to be those vibration measurements
made during the normal operation of a machine. The ISO 20816 series permits the use of different
measurement quantities and methods, provided that they are well-defined and their limitations are set
out, so that the interpretation of the measurements is well-understood.
The evaluation criteria relate only to the vibration produced by the machine itself and not the vibration
transmitted to it from outside.
This document does not include consideration of torsional vibration.
NOTE 3 For torsional vibration, see, for example, ISO 3046-5, ISO 22266-1 or VDI 2039.