ISO 21940-11:2016规定了刚性转子平衡的程序和不平衡公差。它规定 a） 允许剩余不平衡量的大小， b） 修正平面的必要数量， c） 允许剩余不平衡量分配到公差平面，以及 d） 如何解释平衡过程中的错误。 注:在ISO 21940-14中，详细考虑了平衡误差的评估。ISO 19499介绍了转子平衡的基本原理。 ISO 21940-11:2016未涵盖具有柔性行为的转子的平衡。ISO 21940-12规定了挠性转子的程序和公差。

ISO 21940-11:2016 establishes procedures and unbalance tolerances for balancing rotors with rigid behaviour. It specifies a) the magnitude of the permissible residual unbalance, b) the necessary number of correction planes, c) the allocation of the permissible residual unbalance to the tolerance planes, and d) how to account for errors in the balancing process. NOTE In ISO 21940？14, the assessment of balancing errors is considered in detail. Fundamentals of rotor balancing are contained in ISO 19499 which gives an introduction to balancing. ISO 21940-11:2016 does not cover the balancing of rotors with flexible behaviour. Procedures and tolerances for rotors with flexible behaviour are dealt with in ISO 21940？12.