This part of ISO 21940 specifies the requirements for the following:

a) identifying errors in the unbalance measuring process of a rotor;

b) assessing the identified errors;

c) taking the errors into account.

This part of ISO 21940 specifies balance acceptance criteria, in terms of residual unbalance, for both directly

after balancing and for a subsequent check of the balance quality by the user.

For the main typical errors, this part of ISO 21940 lists methods for their reduction in an informative annex.